Ruffed lemur
Encyclopedia
The ruffed lemurs of the genus
Varecia are strepsirrhine
primate
s and the largest extant lemur
s within the family Lemuridae
. Like all living lemurs, they are found only on the island of Madagascar
. Formerly considered to be a monotypic
genus, two species
are now recognized: the black-and-white ruffed lemur
, with its three subspecies
, and the red ruffed lemur
.
Ruffed lemurs are diurnal and arboreal quadruped
s, often observed leaping through the upper canopy of the seasonal tropical rainforest
s in eastern Madagascar. They are also the most frugivorous
of the Malagasy lemurs, and they are very sensitive to habitat disturbance. Ruffed lemurs live in multi-male/multi-female groups and have a complex and flexible social structure, described as fission-fusion
. They are highly vocal, and have loud, raucous calls.
Ruffed lemurs are seasonal breeders and highly unusual in their reproductive strategy. They are considered an "evolutionary enigma" in that they are the largest of the extant species in Lemuridae, yet exhibit reproductive traits more common in small, nocturnal lemurs, such as short gestation
periods (~102 days) and relatively large average litter
sizes (~2–3). Ruffed lemurs also build nests for their newborns (the only primates that do so), carry them by mouth, and exhibit an absentee parental system by stashing them while they forage. Infants are altricial
, although they develop relatively quickly, traveling independently in the wild after 70 days and attaining full adult size by six months.
Threatened by habitat loss and hunting, ruffed lemurs are facing extinction
in the wild. However, they reproduce readily in captivity, and have been gradually re-introduced
into the wild since 1997. Organizations that are involved in ruffed lemur conservation include the Durrell Wildlife Conservation Trust
, the Lemur Conservation Foundation (LCF)
, the Madagascar Fauna Group (MFG)
, Monkeyland Primate Sanctuary in South Africa, Wildlife Trust
, and the Duke Lemur Center (DLC)
.
s are not known in the fossil record on Madagascar until the Pleistocene
and Holocene
epochs. Consequently, little is known about the evolution of ruffed lemurs, let alone the entire lemur clade
, which comprises the endemic primate population of the island.
Although there is still much debate about the origins of lemur
s on Madagascar, it is generally accepted that a single rafting event
, similar to the one that brought New World monkeys to South America
, occurred around 50–80 million years ago and allowed ancestral lemurs to cross the Mozambique Channel
and colonize the island, which had already split from Africa (while it was joined to the Indian subcontinent), approximately 160 million years ago. The resulting founder effect
and either non-existent or inferior competition resulted in speciation
as the lemur ancestors radiated out to fill open or insufficiently guarded niches
. Today, the endemic primate fauna
of Madagascar contains over three-quarters of the extant species of the suborder Strepsirrhini
, which had been abundant throughout Laurasia
and Africa during the Paleocene
and Eocene
epochs
.
The ruffed lemur genus, Varecia, is a member of the family
Lemuridae
. The extinct genus, Pachylemur
most closely resembled the ruffed lemurs but died out after the arrival of humans. The genus Varecia contains two species, red ruffed lemur
s and black-and-white ruffed lemur
s, the latter having three subspecies.
. In 1962, the ruffed lemurs were reassigned to the genus Varecia.
The red ruffed lemur and the black-and-white ruffed lemur were formerly recognized as subspecies, Varecia variegata rubra and Varecia variegata variegata respectively. In 2001 both were elevated to species status, a decision that was later supported by genetic research. Three subspecies of black-and-white ruffed lemur, which had been published decades earlier, were also recognized as variegata, editorum, and subcincta, although studies have not been entirely conclusive.
Subfossil
remains of two extinct lemur species
were previously classified under the genus Varecia. Found at sites in central and southwestern Madagascar, Varecia insignis and V. jullyi were very similar to modern ruffed lemurs, but more robust and assumed to be more terrestrial
, and thus more prone to predation by early human settlers. More recent studies have shown that these extinct species had a diet similar to that of modern ruffed lemurs, and that they were also arboreal in nature. Enough differences were demonstrated to merit a separate genus, Pachylemur
. These close relatives of ruffed lemurs are now named Pachylemur insignis and P. jullyi.
Ruffed lemurs are the largest extant members of the family Lemuridae, with an average head-body length between 43 to 57 cm (16.9 to 22.4 in) and a total length from 100 to 120 cm (39.4 to 47.2 in), while ranging in weight from 3.1 to 4.1 kg (6.8 to 9 lb). The thick, furry tail is longer than the body, averaging 60 and 65 cm (23.6 and 25.6 in) in length and is used primarily for balance while moving through the trees. Ruffed lemurs exhibit neither sexual dimorphism
nor sexual dichromatism, and females have three pairs of mammary gland
s.
Ruffed lemurs are characterized by their long, canine-like
muzzle
, which includes a significant overbite
. The face is mostly black, with furry "ruffs" running from the ears to the neck. Depending on the species, these ruffs are either white (V. variegata) or deep reddish (V. rubra). Likewise, the coloration of the fluffy fur also varies by species, while the coloration pattern varies by subspecies in the black-and-white ruffed lemur
. There are also intermediates in color variation between the two species.
As with all lemurs, the ruffed lemur has special adaptations for grooming
, including a toilet-claw
on its second toe, and a toothcomb
.
s, with the most common type of movement being above-branch quadrupedalism. While in the canopy leaping, vertical clinging, and suspensory behavior
, are also common, while bridging, bimanual movement, and bipedalism are infrequently seen. When moving from tree to tree, ruffed lemurs will look over the shoulder while clinging, launch themselves into the air, and twist mid-air so that their ventral surface lands on the new tree or limb. Suspensory behavior is more common in ruffed lemurs than in other lemur species. When ruffed lemurs come down to the ground, they continue to move quadrupedally, running with bounding hops and the tail held high.
of the lemurs, they thrive only in primary forest with large fruiting trees, where they spend most of their time in the upper canopy. By spending the majority of their time in the crown
of tall forest trees, they are relatively safe from predators such as the fossa
.
Ruffed lemurs are active primarily during the day (diurnal), during which time they feed primarily on fruits and nectar, often utilizing suspensory postures
while feeding. The seeds of the fruit they eat pass through their digestive tract
and are propagated throughout the rainforests in their feces
, helping to ensure new plant growth and a healthy forest ecosystem. These lemurs are also significant pollinator
s of the traveller's tree (Ravenala madagascariensis). Without destroying the inflorescence
, they lick the nectar from deep inside the flower using their long muzzles and tongues, collecting and transferring pollen on their snouts and fur from plant to plant. This relationship is thought to be a result of co-evolution
.
Like all lemurs, this genus is found only on the island of Madagascar off the southeastern coast of Africa
. Confined to the island's seasonal eastern tropical rainforest
s, it is uncommon to rare throughout its range, which historically ran from the Masoala Peninsula
in the northeast to the Mananara River in the south. Today, the black-and-white ruffed lemur
has a much larger range than the red ruffed lemur
, although it is very patchy, extending from slightly northwest of Maroantsetra
, on Antongil Bay
, in the north down the coast to the Mananara River near Vangaindrano
in the south. Additionally, a concentrated population of black-and-white ruffed lemurs, of the subspecies Varecia variegata subcincta, can also be found on the island reserve of Nosy Mangabe
in Antongil Bay. It is suspected that this population was introduced to the island in the 1930s. The red ruffed lemur, on the other hand, has a very restricted range on the Masoala Peninsula.
Historically, the confluence
of the Vohimara and Antainambalana Rivers may have been a zone of hybridization
between these two species, although no conclusive results have indicated current interbreeding. In general, the Antainambalana River appears to isolate
the red ruffed lemurs from the neighboring subspecies of black-and-white ruffed lemur, V. v. subcincta. The subspecies V. v. variegata can be found further south, and V. v. editorum is the southernmost subspecies. The ranges of these two southern subspecies overlap and intermediate forms are reported to exist, although this has not been confirmed.
The rainforests in which these animals live are seasonal, with two primary seasons: the hot, wet season (November through April), and the cool, dry season (May through October). The primary habitat for both species, at any season, is in the crowns of trees, where they spend the majority of their time 15 and 25 m (49.2 and 82 ft) above ground. With the seasonal availability of resources being similar regardless of location, there is little to no difference in tree usage between species. From September through April, more fruit is available, so females prefer the liana
s in the crowns of trees. Both sexes utilize the lower, major branches during the hot, rainy season. The tree crowns are predominantly used from May through August, when young leaves and flowers are in abundance.
Ruffed lemurs either demonstrate feeding dominance or divide resources by using different forest strata. They are dominant over red-bellied lemurs, while eastern lesser bamboo lemurs avoid encountering them all together. White-headed lemurs, on the other hand, utilize the understory
and lower canopy, below 15 m (49.2 ft), while the ruffed lemurs utilize the upper canopy, above 15 m (49.2 ft). Play has even been observed between infant ruffed lemurs and White-headed Lemurs.
over a branch or sunbathing in a supine position
with the limbs outstretched. When feeding, they will often hang upside-down by their hind feet, a type of suspensory behavior
, which allows them to reach fruits and flowers.
Being highly arboreal, they spend the majority of their time in the high canopy throughout the day. Ruffed lemurs spend the majority of their time between 15 to 20 m (49.2 to 65.6 ft) above the forest floor, followed by 20 to 25 m (65.6 to 82 ft) up, and are least frequently seen at 10 to 15 m (32.8 to 49.2 ft). During the hot season, they will relocate to the lower canopy to help regulate their body temperature. In the cold season, ruffed lemurs are least active and may dedicate 2% of their resting time to sunbathing in order to warm up.
Long-term field research has shown that range size, group size, social systems, and territorial behavior vary widely, and may be greatly affected by food distribution and quality. It is generally agreed that the ruffed lemur social system is multi-male/multi-female with a fission-fusion society
, although some populations of black-and-white ruffed lemur have been reported as monogamous. This social flexibility is suspected to improve survivability despite an inflexible feeding ecology.
members of the family Lemuridae, consuming an average of 74–90% fruit, ruffed lemurs also consume nectar (4–21%), and supplement the rest of their diet with young leaves (3–6%), mature leaves (1%), flowers (3–6%), and some seeds. Ruffed lemurs have also been reported to come to the ground to eat fungi
and exhibit geophagy
.
The majority of their diet is made up of relatively few common plant species, with a few species providing more than 50% of the diet. Fig species of the genus Ficus
, for example, account for 78% of the fruit consumed by red ruffed lemurs on the Masoala Peninsula. Although plant species and diets vary by location, the most common food plants reported from the field include the following:
Fruit trees do not appear to be selected by species, but by availability and accessibility of edible fruit. And despite predominance of a few plant species in the ruffed lemur diet, the remainder of their diet consists of between 80 and 132 other species from 36 plant families.
The availability of food reflects the seasonal nature of the forests in which they live. During the hot season, fruit, flowers, and young leaves are more abundant, whereas the cold, wet season offers more young leaves and flowers. Despite this, the diet changes little between seasons, except that females will consume more high-protein, low-fiber items, such as young leaves and flowers, during pregnancy and lactation in order to offset the energy costs of reproduction. Nectar is only available sporadically, yet constitutes a major food source when the flowers bloom. The nectar of the traveller's palm (Ravenala madagascariensis) is a favorite among ruffed lemurs.
s with a fission-fusion
social structure, although this can vary by season and locality.
In a study done at Masoala Peninsula on red ruffed lemurs three levels of organization were identified and defined: communities, core groups, and subgroups. Communities are individuals that affiliated regularly with each other, but rarely with conspecifics
outside of the community. Although the entire multi-male/multi-female community lives within a discrete home range, all individuals are never seen in the same location at the same time. Instead, individuals form dispersed social networks, known as core groups, within the community. Core groups are individuals that shared the same core area within a community territory throughout the year. Core groups typically consist of two reproductive females, as well as reproductive males and subadults, ranging in size from two individuals to nine. Females within the groups are cooperative, but male encounters are often agonistic. Subgroups, on the other hand, vary daily in size, composition, and duration, and consist of associated individuals from either the same core group or different core groups, depending on the season. It is from the consistent, daily changes in these subgroups that occur throughout the year, as well as the seasonal formations of core groups in core areas, that demonstrate the fission-fusion nature of ruffed lemur social structure.
In another study done at Nosy Mangabe
on black-and-white ruffed lemurs a fourth level or organization was defined: affiliates. Affiliates were individuals with more persistent social bonds and more frequent interactions, usually within a core group, but sometimes also between core groups within a subgroup. Adult females typically had many affiliates, whereas adult males rarely interacted with conspecifics, living a more solitary existence.
Past studies have reported other social organizations in ruffed lemurs including monogamous
pair bonding. This may have been due to the use of short-term, seasonal field studies instead of yearlong studies that take into consideration the effects that changing seasons have on ruffed lemur communities. For instance, during the cold, rainy season, which corresponds with the breeding season, interactions between core groups within a community are significantly reduced. During this time small subgroups form consisting of a mature female, a mature male, and sometimes offspring. This can be misinterpreted as monogamous pair bonding.
Ranging behavior can also exhibit seasonal variability. During the hot, wet season, females range widely, either alone or in groups of up to six individuals. In the cool, dry season, smaller core groups stabilize in order to occupy concentrated areas. Therefore, during seasons when fruit is abundant, subgroups are larger while scarcity is met with more solitary behavior. This suggests that although their feeding ecology is inflexible, being tied to widely distributed, patchy, and sometimes scarce fruit, ruffed lemurs instead adapt the social system in order to survive.
In terms of dominance, the ruffed lemur's social structure is not as clear-cut as other lemur societies where female dominance
is the norm. Although it is historically reported that "males were subordinate to females," especially with captive and free-ranging ruffed lemur populations demonstrating this, wild populations cannot be definitively labeled as matriarchal
due to inter-group variation.
There are also social differences between males and females. Females typically have many affiliates and bond strongly with other females both within and outside their core areas, but do not affiliate with individuals outside the community range, except during mating season. Males, on the other hand, are more solitary, interact with only a couple of conspecifics, have weak social bonds with other males, and rarely associate with others outside their core group. Furthermore, field studies suggest that only females play a role in communal home range defense. Males may scent-mark and remain relatively silent, but otherwise show little involvement during disputes.
Community range or territory
size can vary widely, from 16 ha (0.16 km²; 0.0617763453748056 sq mi) while group size can range from a single pair to 31 individuals. Population density
is also noticeably variable. These wide ranges can be attributed to differing levels of protection and degree of environmental degradation, with better protection and a less degraded environment resulting in higher population density and more moderately sized community ranges. (The duration and seasonality of the studies involved may also have contributed to low group size estimates and community ranges. A study at the Betampona Reserve
, for instance, observed monogamous pairs with two to five infants maintaining ranges of 16 ha (0.16 km²; 0.0617763453748056 sq mi).) Core areas at Ambatonikonilahy
constituted approximately 10% of the overall community range and showed a close relationship with the location of the largest fruiting trees.
The average daily traveling distance for ruffed lemurs varies between 436 to 2250 m (1,430.4 to 7,381.9 ft), averaging 1129 metres (3,704.1 ft) per day. Activity patterns within the community range vary by gender and season. Males generally stay within a core area all year, whereas females only confine themselves to a core area during the cold wet season, then expand their range throughout the community range during the hot, rainy season. Females expand their traveling range slightly after giving birth, still staying within the core area, but gradually range further in December when they begin stashing their infants with other community members while they look for food. Females range the furthest later during the hot, rainy season. Both activity level and reproductive activity can be summarized in the following table.
Although males demonstrate little involvement in territorial disputes between neighboring communities, and ruffed lemur communities lack cohesiveness, females communally defend the community range against females of other communities. These disputes occur mostly during the hot, rainy season, when resources are more abundant and occur near the boundaries of community ranges. Spacing is maintained by scent marking and vocal communication. Ruffed lemurs are known for their loud, raucous calls that are answered by neighboring communities and subgroups within the same community.
During agonistic encounters between communities, chasing, scent-marking, calling, and occasional physical contact can be seen. Other social behaviors appear to vary between wild and captive ruffed lemurs, as illustrated by the following table.
Some affiliative behaviors are seasonal or gender-specific, such as the male squeal approach and anogenital inspections performed during the mating season. Another example is the female greeting behavior, where two females will use their anogenital scent glands to mark each other's backs, jump over one another, writhe together, and emit squealing vocalizations. This behavior is not seen during the end of the cool, dry season or around gestation. The frequency of other affiliative behaviors can be affected by age. All ruffed lemurs over five months of age allogroom
, and, in captivity, subadults participate in play more frequently than adults.
and cognition
have been performed on strepsirrhine primates, including ruffed lemurs. However, a study at the Myakka City Lemur Reserve demonstrated that ruffed lemurs, along with several other members of the family Lemuridae, could understand the outcome of simple arithmetic operations.
primates, olfactory
communication is used extensively by ruffed lemurs – scent marking in territorial defense and disputes, as well as female greeting displays. The scents communicate the sex, location, and identity of their owner.
Females predominantly scent mark with their anogenital scent gland
s, by squatting to rub their anogenital region along horizontal surfaces, such as tree limbs. Males, on the other hand, favor using the glands on their neck, muzzle, and chest, by embracing horizontal and vertical surfaces and rubbing themselves over them. Both sexes will occasionally scent mark in ways characteristic of the opposite sex.
In greeting displays, female ruffed lemurs will leap over one another, scent marking the other individual's back in the process.
Ruffed lemurs utilize alarm calls that differentiate between ground and aerial predators. For instance an abrupt roar or huff alerts the group to an avian predator, and a pulsed squawk or growl-snort communicates the existence of a mammalian ground predator. When sounding these calls, such as the pulsed squawk, adults direct them at the predator after moving to a safe position. Once the alarm call is sounded by one individual, the resulting chorus can even reach the furthest ranging community members.
In captivity, ruffed lemur vocalizations have been studied and divided into three general groups: high-, medium-, and low-amplitude calls.
The well-known roar/shriek chorus is spontaneous, occurring most often during period of high activity, as well as being contagious, involving communal participation including infants three to four months old. Abrupt roars are also more common during high activity and aside from alerting group members to the presence of an avian predator, they probably also help maintain contact with individuals outside of visual range or indicate an aggressive/defensive response to a disturbance. In the wild, both of these calls are emitted more during the hot, rainy season due to heighten activity. All high-amplitude calls are delivered with from a "taut" body posture.
Medium-amplitude calls operate over a shorter range or often involve moderately arousing situations, such as frustration or submission. Low-amplitude calls also generally operate over a short range, yet also cover a wider range of aggravation levels.
Whines are highly variable between individual ruffed lemurs. Cough, grumble, squeak, and squeal have only been observed and researched in the wild.
The calls of ruffed lemurs vary only slightly between the two species. In fact, in captivity, it has been documented that red ruffed lemurs understand and even join in the alarm calls of black-and-white ruffed lemurs. One minor difference between the vocal repertoires of these two species is in the pulse rate and frequency of the pulsed squawk, which is much faster and higher in red ruffed lemurs than in black-and-white ruffed lemurs. The difference in this vocalization is only interspecific, showing no signs of significant sexual dimorphism within each species.
Red ruffed lemurs do not appear to produce a bona fide wail vocalization. In black-and-white ruffed lemurs, pulsed squawks sometimes slow down as the group calms down, and integrate with the wail, creating pulsed squawk-wail intermediates . red ruffed lemurs also produce pulsed squawk-wail intermediate sounds, but they do not exhibit long, drawn-out wails like the black-and-white ruffed lemurs.
Shortly before mating season begins, females exhibit swelling of the sex skin, which reaches its peak around the middle of their 14.8 day estrous cycle
. Male sexual physiology also undergoes its own change, with testicular volume increasing during mating season, peaking around the time of breeding. Aggression also increases during the mating season, both between members of the same sex and by females towards the male attempting to mate with her. Females have been observed grappling, cuffing, and biting the male during copulation
. Either sex may approach the other when the female is in estrus. Initially they may roar-shriek with each other. When a male approaches a female he often lowers his head and squeals, inspecting the female's genitalia by licking or sniffing, scent-marking, and offering a submissive chattering vocalization. When a female approaches a male, she may posture herself for mounting. Mating pairs often copulate many times during the course of a mating bout.
The mating season lasts from May through July, during the cold, rainy season, resulting in birth and peak lactation
coinciding with the time that fruit is the most plentiful. The gestation
period of ruffed lemurs is the shortest of the family Lemuridae, averaging 102 days (with a range of 90 to 106 days). Gestation in the wild last slightly longer than in captivity, averaging 106 days. Just like the mating season, parturition is also seasonal, synchronized to the end of the cold, dry season and the start of the productive hot, rainy season.
In addition to an abnormally short gestation period, ruffed lemurs share another feature with small, nocturnal lemurs by producing the largest litters
of the family Lemuridae. Litters typically include two or three infants, although up to five have been reported. Birth weights in captivity average between 83 to 101.7 g (2.9 to 3.6 oz) and range from 70 to 140 g (2.5 to 4.9 oz). Ruffed lemur infants are altricial
, and are born with their eyes open and a full coat of fur.
Ruffed lemurs are the only known primates to build arboreal nests, used exclusively for birth and for the first week or two of life. Starting three weeks prior to birth, females begin constructing the nest from twigs, branches, leaves, and vines, locating it within her core area and 10 to 25 m (32.8 to 82 ft) above ground. The nests have only one apparent entry point, and are shallow and dish-shaped. During the first couple of weeks, the mother is mostly solitary and does not travel far from the nest, spending as much as 70–90% of her time with the newborns (in captivity). In order to find food, she will leave the infants alone in the nest or, after the first couple of weeks, will carry them in her mouth and stash them in concealed locations in the canopy while she forages. Since this early developmental period corresponds with the end of the cold, dry season, which offers the least amount of fruit, energy is conserved for lactation while travel is limited. As the hot, rainy season begins, fruit availability rises, lactation demands rise as well, and females increase their travel distance in search of food.
Unlike other diurnal primates, which usually carry their infants with them, ruffed lemur mothers will stash their young by concealing them in the canopy foliage, leaving them to rest and sit quietly for several hours while she forages and performs other activities. Mothers continue to transport their offspring by mouth, moving them one at a time by grasping the infant's belly crosswise. This form of transport usually stops around 2.5 months of age when the infants become too heavy to carry.
Ruffed lemurs are cooperative breeders
, with parental care being shared by all community members. For example, mothers will stash their offspring with other mothers or leave them to be guarded by other community members, including non-breeding individuals of both genders. While the mother is away, community members will not only care for and guard them, but also sound alarm calls if danger is detected or if leaving the infant alone. They will also respond to alarm calls by others. These coordinated vigilance displays further involve communal transmission of the alarm call, with nearby community members repeating the alarm call, potentially summoning the mother back to her offspring. Infant transport by other members of the community has also been recorded. Females have been observed nursing infants of their close relatives, while close kin have adopted rejected infants, acting as foster parents.
Male care for infants has been documented in ruffed lemur societies. During early development, adult males may guard the nests of multiple core group females, as well as help care for the infants that were likely fathered by other males. During the season when females practice infant stashing, males effectively lighten the reproductive burden of up to several mothers by guarding, huddling, grooming, travelling, playing with and feeding the young.
Female ruffed lemurs produce relatively rich milk compared to other lemurs, and consequently, their young develop faster than those of other lemurs. Infants develop rapidly, attaining approximately 70–75% adult weight by the age of four months. They begin climbing and clinging at one month of age, advancing to the point of independently following their mother and group members through the canopy at heights of 50 to 100 m (164 to 328.1 ft) by two to three months. Full adult mobility is attained at three to four months of age. Socially, they begin exchanging contact calls with their mother at three weeks, and select their mother as their play partner 75–80% of the time during the first three months. Participation in greeting displays and utilization of more extensive vocalizations commences around four months, while scent marking does not start until six months of age. Infants begin testing solid food starting around 40 days to two months with weaning occurring between four to six months in the wild, although some individuals have continued to nurse until seven to eight months.
Infant mortality is often high among ruffed lemurs, but can also be highly variable. In some seasons, as many as 65% are unable to reach three months of age, possibly due to falls and related injuries, although in some seasons infant mortality is as low as 0%. For those that do survive to adulthood, sexual maturity is attained at 18 to 20 months in females and 32 to 48 months in males. Sexual maturity may take longer to reach in the wild compared to captivity. For females, the inter-birth interval, or time between successive offspring, is typically one year, and in captivity, females can remain reproductively active until the age of 23. The life expectancy for both species of ruffed lemur is estimated at 36 years in captivity, although it is likely to be considerably less in the wild.
resulting in significantly lower population densities
. Although they can survive in very disturbed habitats with lower population densities, they are still especially vulnerable to habitat disturbance. Decreased genetic diversity, in tandem with hunting, natural disasters, predation, and disease, can easily wipe out small populations.
The black-and-white ruffed lemur
was elevated by the IUCN to Critically Endangered (A2cd) status from Endangered status in 2008. They cite that "the species is believed to have undergone a decline of 80% over a period of 27 years, due primarily to a decline in area and quality of habitat within the known range of the species and due to levels of exploitation." The total area of all known localities in which black-and-white ruffed lemurs exist is estimated at less than 8000 km² (3,088.8 sq mi), while the total wild population is estimated between 1,000 and 10,000.
The red ruffed lemur
was downgraded to Endangered status from Critically Endangered status by the IUCN in 2008. The justification given includes its limited range, its restriction to only the Masoala Peninsula, and its risk from ongoing habitat loss and hunting. This species occupies a range of no more than 4000 km² (1,544.4 sq mi), while the total wild population is estimated between 29,000 and 52,000 individuals. Red ruffed lemurs are only protected within the boundaries of the Masoala National Park
. Historically, this species has been considered more threatened due to its highly restricted range, compared to the widely distributed black-and-white ruffed lemur. However, its protection within the island's largest national park has slightly improved its chances at survival.
There are several organizations involved in ruffed lemur conservation, including the Durrell Wildlife Conservation Trust
, the Lemur Conservation Foundation (LCF)
, the Madagascar Fauna Group (MFG)
, Monkeyland Primate Sanctuary in South Africa, Wildlife Trust
, and the Duke Lemur Center (DLC)
. To conservation organizations, the ruffed lemurs are considered indicator
, umbrella
, and flagship species
.
, and mining
. Both species appear to be very sensitive to logging, and are thought to be the most vulnerable of rainforest lemurs. The hardwood
s that are favored for construction materials and selectively logged are also preferred by ruffed lemurs for their fruits and potentially affect their travel routes through the canopy. Deforestation
, on the other hand, is a result of the need to provide firewood and to support subsistence agriculture
and cash crop
s. For red ruffed lemurs, Slash-and-burn agriculture, known locally as tavy, is practiced seasonally on the Masoala peninsula between October and December, and its practice is expanding. Additionally, cattle are sometimes allowed to free-range over these former agricultural clearings, preventing forest re-growth.
Another principal threat to the survival of ruffed lemurs is hunting. Local human populations still hunt and trap ruffed lemurs with traditional weapons, using them as a source of subsistence. Studies from villages in the Makira Forest have revealed that ruffed lemur meat is not only a desired food, but is being hunted unsustainably. On the Masoala peninsula, the calls of red ruffed lemurs help hunters locate them. On this peninsula, firearms are used in addition to traditional traps, known as laly, which involve a 5 metres (16.4 ft) strip of cleared forest with snares set on the few remaining branches that allow the lemurs to cross. Although hunting is illegal, the laws are generally not enforced and the local inhabitants show little concern about their hunting practices, which occur mostly from May to September. Hunting is the biggest concern in the Masoala peninsula because it is likely to continue, whereas logging and slash-and-burn agriculture could be curtailed. In other regions, hunters can scare away ruffed lemurs from their favorite food sources, even if they are hunting other prey. Lastly, these animals are taken from their natural habitats to display for tourists or are sold as exotic pet
s.
Frequent cyclone
s also pose a threat, particularly to concentrated or small populations. In late January 1997, cyclone Gretelle destroyed 80% of the Manombo forest canopy. With their habitat, including most of their food resources, effectively destroyed, the ruffed lemurs of the forest broadened their diet, remaining surprisingly frugivorous. Their body weights dropped and no births were reported for four years, but they managed to stave off starvation. This event demonstrated not only their flexibility in the face of natural disasters, which may highlight the evolutionary reasons behind their reproductive capacity and litter size, but also the threat faced by already stressed populations.
Predation in the wild appears to be very rare for ruffed lemurs, probably because living in the high canopy makes them challenging to catch. Evidence of predation by raptors, such as the Henst's goshawk
(Accipiter henstii) suggests it occurs at a low rate. The fossa
(Cryptoprocta ferox) could present a potential risk if it found an individual lower in the forest canopy, but no confirmation has been presented to indicate that they prey upon ruffed lemurs. Instead, only re-introduced, captive-bred ruffed lemurs have been killed by fossa, likely due to their inexperience with predators. Nesting behavior poses the biggest risk of predation, making them susceptible to carnivorous mammals, such as the ring-tailed mongoose
(Galidia elegans) and brown-tailed mongoose
(Salanoia concolor).
is managed by the Species Survival Plan (SSP)
, a program developed by the Association of Zoos and Aquariums (AZA)
. Although the populations are very limited in their genetic diversity, these species thrive in captivity, making them an ideal candidate for reintroduction
into protected habitat, if it is available. Although reintroduction is seen as a last resort among conservationists
, a combination of in situ conservation efforts, such as legal protection, public education, the spread of sustainable livelihoods
, and reforestation
offer hope for ruffed lemurs. In the meantime, reintroductions offer conservation research opportunities and allow the limited genetic diversity maintained by the SSP to improve the genetic diversity of dwindling Malagasy ruffed lemur populations.
A captive release first occurred in November 1997, when five black-and-white ruffed lemurs (Varecia variegata variegata) born in the United States were returned to Madagascar for release in the Betampona Strict Nature Reserve
in eastern Madagascar. Popularly known as the Carolina Five, these individuals had lived their entire lives in the Natural Habitat Enclosures at the Duke Lemur Center (DLC). Since then, two more groups totaling 13 captive-born ruffed lemurs have been reintroduced into the same reserve, once in November 1998 and again in January 2001. These latter two groups also received "boot camp training" in the DLC forested free-range enclosures prior to release. So far, the results have shown some success, with 10 surviving longer than one year, 3 individuals integrating into wild groups, and 4 offspring have been born to or sired by released lemurs, all of which were parent-raised. Saraph, a male released with the first group, was reported to be doing well seven years post-release, living in a social group with a wild female and their offspring. Research has been ongoing since the initial release, as illustrated in the 1998 BBC
documentary In the Wild: Operation Lemur with John Cleese
. The research has provided useful information about their adaptation to life in the wild.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Varecia are strepsirrhine
Strepsirrhini
The clade Strepsirrhini is one of the two suborders of primates. Madagascar's only non-human primates are strepsirrhines, and others can be found in southeast Asia and Africa...
primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s and the largest extant lemur
Lemur
Lemurs are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species...
s within the family Lemuridae
Lemuridae
Lemuridae is a family of prosimian primates native to Madagascar, and one of five families commonly known as lemurs. These animals were thought to be the evolutionary predecessors of monkeys and apes, but this is no longer considered correct...
. Like all living lemurs, they are found only on the island of Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
. Formerly considered to be a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus, two species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are now recognized: the black-and-white ruffed lemur
Black-and-white ruffed lemur
The black-and-white ruffed lemur is the more endangered of the two species of ruffed lemurs, both of which are endemic to the island of Madagascar. Despite having a larger range than the red ruffed lemur, it has a much smaller population that is spread out, living in lower population densities...
, with its three subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
, and the red ruffed lemur
Red Ruffed Lemur
The red ruffed lemur is one of two species in the genus Varecia, the ruffed lemurs; the other is the black-and-white ruffed lemur . Like all lemurs, it is native to Madagascar and occurs only in the rainforests of Masoala, in the northeast of the island...
.
Ruffed lemurs are diurnal and arboreal quadruped
Quadruped
Quadrupedalism is a form of land animal locomotion using four limbs or legs. An animal or machine that usually moves in a quadrupedal manner is known as a quadruped, meaning "four feet"...
s, often observed leaping through the upper canopy of the seasonal tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
s in eastern Madagascar. They are also the most frugivorous
Frugivore
A frugivore is a fruit eater. It can be any type of herbivore or omnivore where fruit is a preferred food type. Because approximately 20% of all mammalian herbivores also eat fruit, frugivory is considered to be common among mammals. Since frugivores eat a lot of fruit they are highly dependent...
of the Malagasy lemurs, and they are very sensitive to habitat disturbance. Ruffed lemurs live in multi-male/multi-female groups and have a complex and flexible social structure, described as fission-fusion
Fission-fusion society
In primatology, a fission-fusion society is one in which the social group, e.g. bonobo collectives of 100-strong, sleep in one locality together, but forage in small groups going off in different directions during the day. This form of social organization occurs in several other species of...
. They are highly vocal, and have loud, raucous calls.
Ruffed lemurs are seasonal breeders and highly unusual in their reproductive strategy. They are considered an "evolutionary enigma" in that they are the largest of the extant species in Lemuridae, yet exhibit reproductive traits more common in small, nocturnal lemurs, such as short gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
periods (~102 days) and relatively large average litter
Litter (animal)
A litter is the offspring at one birth of animals from the same mother and usually from one set of parents. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from...
sizes (~2–3). Ruffed lemurs also build nests for their newborns (the only primates that do so), carry them by mouth, and exhibit an absentee parental system by stashing them while they forage. Infants are altricial
Altricial
Altricial, meaning "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born...
, although they develop relatively quickly, traveling independently in the wild after 70 days and attaining full adult size by six months.
Threatened by habitat loss and hunting, ruffed lemurs are facing extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
in the wild. However, they reproduce readily in captivity, and have been gradually re-introduced
Reintroduction
Reintroduction is the deliberate release of a species into the wild in zones formerly inhabited by said species but where it has disappeared from for a number of reasons, from captivity or relocated from other areas where the species still survives in...
into the wild since 1997. Organizations that are involved in ruffed lemur conservation include the Durrell Wildlife Conservation Trust
Durrell Wildlife Conservation Trust
Durrell Wildlife Conservation Trust is a conservation organisation with a mission to save species from extinction.Gerald Durrell founded the Jersey Wildlife Preservation Trust as a charitable institution in 1963 with the Dodo as its symbol...
, the Lemur Conservation Foundation (LCF)
Lemur Conservation Foundation
The Lemur Conservation Foundation is a small American non-profit organization that works closely with the Duke Lemur Center, LCF Scientific Advisory Council , the Association of Zoos and Aquariums Prosimian Taxon Advisory Group , and the Species Survival Plan coordinators...
, the Madagascar Fauna Group (MFG)
Madagascar Fauna Group
The Madagascar Fauna Group or MFG is an international consortium of zoos and other conservation agencies which pool together resources to help conserve animal species in Madagascar, through captive breeding programs, field research programs, training programs for rangers and wardens, and...
, Monkeyland Primate Sanctuary in South Africa, Wildlife Trust
Wildlife Trust (US)
EcoHealth Alliance, formerly known as Wildlife Trust, is a non-profit, non-governmental organization headquartered in New York City working on conservation ecology and issues in the United States and around the world....
, and the Duke Lemur Center (DLC)
Duke Lemur Center
The Duke Lemur Center is an sanctuary for rare and endangered prosimian primates, located at Duke University in Durham, North Carolina. It is the largest sanctuary for prosimian primates in the world....
.
Evolutionary history
LemurLemur
Lemurs are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species...
s are not known in the fossil record on Madagascar until the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
and Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
epochs. Consequently, little is known about the evolution of ruffed lemurs, let alone the entire lemur clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
, which comprises the endemic primate population of the island.
Although there is still much debate about the origins of lemur
Lemur
Lemurs are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species...
s on Madagascar, it is generally accepted that a single rafting event
Rafting event
Oceanic dispersal is a type of biological dispersal that occurs when organisms transfer from one land mass to another by way of a sea crossing on large clumps of floating vegetation. Such matted clumps of vegetation are often seen floating down major rivers in the tropics and washing out to sea,...
, similar to the one that brought New World monkeys to South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, occurred around 50–80 million years ago and allowed ancestral lemurs to cross the Mozambique Channel
Mozambique Channel
The Mozambique Channel is a portion of the Indian Ocean located between the island nation of Madagascar and southeast Africa, primarily the country of Mozambique. It was a World War II clashpoint during the Battle of Madagascar...
and colonize the island, which had already split from Africa (while it was joined to the Indian subcontinent), approximately 160 million years ago. The resulting founder effect
Founder effect
In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using existing theoretical work by those such as Sewall...
and either non-existent or inferior competition resulted in speciation
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
as the lemur ancestors radiated out to fill open or insufficiently guarded niches
Ecological niche
In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...
. Today, the endemic primate fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...
of Madagascar contains over three-quarters of the extant species of the suborder Strepsirrhini
Strepsirrhini
The clade Strepsirrhini is one of the two suborders of primates. Madagascar's only non-human primates are strepsirrhines, and others can be found in southeast Asia and Africa...
, which had been abundant throughout Laurasia
Laurasia
In paleogeography, Laurasia was the northernmost of two supercontinents that formed part of the Pangaea supercontinent from approximately...
and Africa during the Paleocene
Paleocene
The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...
and Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
epochs
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...
.
Taxonomic classification
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Lemuridae
Lemuridae
Lemuridae is a family of prosimian primates native to Madagascar, and one of five families commonly known as lemurs. These animals were thought to be the evolutionary predecessors of monkeys and apes, but this is no longer considered correct...
. The extinct genus, Pachylemur
Pachylemur
Pachylemur is an extinct genus of lemur most closely related to the ruffed lemurs . Its two representative species, Pachylemur insignis and Pachylemur jullyi, are only known from subfossil remains found at sites in central and southwestern Madagascar...
most closely resembled the ruffed lemurs but died out after the arrival of humans. The genus Varecia contains two species, red ruffed lemur
Red Ruffed Lemur
The red ruffed lemur is one of two species in the genus Varecia, the ruffed lemurs; the other is the black-and-white ruffed lemur . Like all lemurs, it is native to Madagascar and occurs only in the rainforests of Masoala, in the northeast of the island...
s and black-and-white ruffed lemur
Black-and-white ruffed lemur
The black-and-white ruffed lemur is the more endangered of the two species of ruffed lemurs, both of which are endemic to the island of Madagascar. Despite having a larger range than the red ruffed lemur, it has a much smaller population that is spread out, living in lower population densities...
s, the latter having three subspecies.
- Family LemuridaeLemuridaeLemuridae is a family of prosimian primates native to Madagascar, and one of five families commonly known as lemurs. These animals were thought to be the evolutionary predecessors of monkeys and apes, but this is no longer considered correct...
- Genus Eulemur: true lemurs
- Genus Hapalemur: lesser bamboo lemurs
- Genus LemurRing-tailed LemurThe ring-tailed lemur is a large strepsirrhine primate and the most recognized lemur due to its long, black and white ringed tail. It belongs to Lemuridae, one of five lemur families. It is the only member of the Lemur genus. Like all lemurs it is endemic to the island of Madagascar...
: the ring-tailed lemur - Genus †PachylemurPachylemurPachylemur is an extinct genus of lemur most closely related to the ruffed lemurs . Its two representative species, Pachylemur insignis and Pachylemur jullyi, are only known from subfossil remains found at sites in central and southwestern Madagascar...
- Genus Prolemur: the greater bamboo lemur
- Genus Varecia: ruffed lemurs
- black-and-white ruffed lemurBlack-and-white ruffed lemurThe black-and-white ruffed lemur is the more endangered of the two species of ruffed lemurs, both of which are endemic to the island of Madagascar. Despite having a larger range than the red ruffed lemur, it has a much smaller population that is spread out, living in lower population densities...
, Varecia variegata- Variegated black-and-white ruffed lemur, Varecia variegata variegata
- Southern black-and-white ruffed lemur, Varecia variegata editorum
- Northern black-and-white ruffed lemur, Varecia variegata subcincta
- red ruffed lemurRed Ruffed LemurThe red ruffed lemur is one of two species in the genus Varecia, the ruffed lemurs; the other is the black-and-white ruffed lemur . Like all lemurs, it is native to Madagascar and occurs only in the rainforests of Masoala, in the northeast of the island...
, Varecia rubra
- black-and-white ruffed lemur
Changes in taxonomy
Ruffed lemurs, along with several species of brown lemur were once included in the genus LemurRing-tailed Lemur
The ring-tailed lemur is a large strepsirrhine primate and the most recognized lemur due to its long, black and white ringed tail. It belongs to Lemuridae, one of five lemur families. It is the only member of the Lemur genus. Like all lemurs it is endemic to the island of Madagascar...
. In 1962, the ruffed lemurs were reassigned to the genus Varecia.
The red ruffed lemur and the black-and-white ruffed lemur were formerly recognized as subspecies, Varecia variegata rubra and Varecia variegata variegata respectively. In 2001 both were elevated to species status, a decision that was later supported by genetic research. Three subspecies of black-and-white ruffed lemur, which had been published decades earlier, were also recognized as variegata, editorum, and subcincta, although studies have not been entirely conclusive.
Subfossil
Subfossil
Subfossil refers to remains whose fossilization process is not complete, either for lack of time or because the conditions in which they were buried were not optimal for fossilization....
remains of two extinct lemur species
Subfossil lemur
Subfossil lemurs are lemurs from Madagascar that are represented by recent remains dating from nearly 26,000 years ago to approximately 560 years ago. They include both living and extinct species, although the term more frequently refers to the extinct giant lemurs...
were previously classified under the genus Varecia. Found at sites in central and southwestern Madagascar, Varecia insignis and V. jullyi were very similar to modern ruffed lemurs, but more robust and assumed to be more terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
, and thus more prone to predation by early human settlers. More recent studies have shown that these extinct species had a diet similar to that of modern ruffed lemurs, and that they were also arboreal in nature. Enough differences were demonstrated to merit a separate genus, Pachylemur
Pachylemur
Pachylemur is an extinct genus of lemur most closely related to the ruffed lemurs . Its two representative species, Pachylemur insignis and Pachylemur jullyi, are only known from subfossil remains found at sites in central and southwestern Madagascar...
. These close relatives of ruffed lemurs are now named Pachylemur insignis and P. jullyi.
Anatomy and physiology
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
nor sexual dichromatism, and females have three pairs of mammary gland
Mammary gland
A mammary gland is an organ in mammals that produces milk to feed young offspring. Mammals get their name from the word "mammary". In ruminants such as cows, goats, and deer, the mammary glands are contained in their udders...
s.
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
muzzle
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
, which includes a significant overbite
Malocclusion
A malocclusion is a misalignment of teeth or incorrect relation between the teeth of the two dental arches. The term was coined by Edward Angle, the "father of modern orthodontics", as a derivative of occlusion, which refers to the manner in which opposing teeth meet.-Presentation:Most people have...
. The face is mostly black, with furry "ruffs" running from the ears to the neck. Depending on the species, these ruffs are either white (V. variegata) or deep reddish (V. rubra). Likewise, the coloration of the fluffy fur also varies by species, while the coloration pattern varies by subspecies in the black-and-white ruffed lemur
Black-and-white ruffed lemur
The black-and-white ruffed lemur is the more endangered of the two species of ruffed lemurs, both of which are endemic to the island of Madagascar. Despite having a larger range than the red ruffed lemur, it has a much smaller population that is spread out, living in lower population densities...
. There are also intermediates in color variation between the two species.
As with all lemurs, the ruffed lemur has special adaptations for grooming
Personal grooming
Personal grooming is the art of cleaning, grooming, and maintaining parts of the body. It is a species-typical behavior that is controlled by neural circuits in the brain.- In humans :...
, including a toilet-claw
Toilet-claw
A toilet-claw is the specialized claw or nail on the foot of certain primates, used for personal grooming. All prosimians have a toilet claw, but the digit that is specialized in this manner varies. Tarsiers have a toilet claw on toe two and toe three...
on its second toe, and a toothcomb
Toothcomb
A toothcomb is an anatomical structure found in strepsirrhine primates, which includes lemurs, lorises and galagos. A toothcomb consists of long, flat forward-angled teeth, and includes the lower incisors and the canine teeth...
.
Locomotion
Ruffed lemurs are considered arboreal quadrupedQuadruped
Quadrupedalism is a form of land animal locomotion using four limbs or legs. An animal or machine that usually moves in a quadrupedal manner is known as a quadruped, meaning "four feet"...
s, with the most common type of movement being above-branch quadrupedalism. While in the canopy leaping, vertical clinging, and suspensory behavior
Suspensory behavior
Suspensory Behavior, exhibited by primates, is a form of arboreal locomotion or a feeding behavior which involves hanging or suspension of the body below or among the branches, rather than moving or sitting on top of the branches...
, are also common, while bridging, bimanual movement, and bipedalism are infrequently seen. When moving from tree to tree, ruffed lemurs will look over the shoulder while clinging, launch themselves into the air, and twist mid-air so that their ventral surface lands on the new tree or limb. Suspensory behavior is more common in ruffed lemurs than in other lemur species. When ruffed lemurs come down to the ground, they continue to move quadrupedally, running with bounding hops and the tail held high.
Ecology
Being highly arboreal and the most frugivorousFrugivore
A frugivore is a fruit eater. It can be any type of herbivore or omnivore where fruit is a preferred food type. Because approximately 20% of all mammalian herbivores also eat fruit, frugivory is considered to be common among mammals. Since frugivores eat a lot of fruit they are highly dependent...
of the lemurs, they thrive only in primary forest with large fruiting trees, where they spend most of their time in the upper canopy. By spending the majority of their time in the crown
Crown (botany)
The crown of a plant refers to the totality of the plant's aboveground parts, including stems, leaves, and reproductive structures. A plant canopy consists of one or more plant crowns growing in a given area....
of tall forest trees, they are relatively safe from predators such as the fossa
Fossa (animal)
The fossa is a cat-like, carnivorous mammal that is endemic to Madagascar. It is a member of the Eupleridae, a family of carnivorans closely related to the mongoose family . Its classification has been controversial because its physical traits resemble those of cats, yet other traits suggest a...
.
Ruffed lemurs are active primarily during the day (diurnal), during which time they feed primarily on fruits and nectar, often utilizing suspensory postures
Suspensory behavior
Suspensory Behavior, exhibited by primates, is a form of arboreal locomotion or a feeding behavior which involves hanging or suspension of the body below or among the branches, rather than moving or sitting on top of the branches...
while feeding. The seeds of the fruit they eat pass through their digestive tract
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
and are propagated throughout the rainforests in their feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
, helping to ensure new plant growth and a healthy forest ecosystem. These lemurs are also significant pollinator
Pollinator
A pollinator is the biotic agent that moves pollen from the male anthers of a flower to the female stigma of a flower to accomplish fertilization or syngamy of the female gamete in the ovule of the flower by the male gamete from the pollen grain...
s of the traveller's tree (Ravenala madagascariensis). Without destroying the inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
, they lick the nectar from deep inside the flower using their long muzzles and tongues, collecting and transferring pollen on their snouts and fur from plant to plant. This relationship is thought to be a result of co-evolution
Co-evolution
In biology, coevolution is "the change of a biological object triggered by the change of a related object." Coevolution can occur at many biological levels: it can be as microscopic as correlated mutations between amino acids in a protein, or as macroscopic as covarying traits between different...
.
Geographic range and habitat
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. Confined to the island's seasonal eastern tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
s, it is uncommon to rare throughout its range, which historically ran from the Masoala Peninsula
Masoala National Park
Masoala National Park, in northeast Madagascar, is the largest of the island's protected areas. Most of the park is situated in Sava Region and a part in Analanjirofo. Created in 1997, the park protects 2,300 square kilometres of rainforest and 100 square kilometres of marine parks. The Masoala...
in the northeast to the Mananara River in the south. Today, the black-and-white ruffed lemur
Black-and-white ruffed lemur
The black-and-white ruffed lemur is the more endangered of the two species of ruffed lemurs, both of which are endemic to the island of Madagascar. Despite having a larger range than the red ruffed lemur, it has a much smaller population that is spread out, living in lower population densities...
has a much larger range than the red ruffed lemur
Red Ruffed Lemur
The red ruffed lemur is one of two species in the genus Varecia, the ruffed lemurs; the other is the black-and-white ruffed lemur . Like all lemurs, it is native to Madagascar and occurs only in the rainforests of Masoala, in the northeast of the island...
, although it is very patchy, extending from slightly northwest of Maroantsetra
Maroantsetra
Maroantsetra is a market town and domestic seaport in Analanjirofo Region, Madagascar. It is located on the Bay of Antongil near .Maroantsetra is the main point of access to Masoala National Park and the Nosy Mangabe special reserve, and the headquarters of the park authority.Access to the town is...
, on Antongil Bay
Antongil Bay
Helodranon' Antongila , more commonly called Antongil Bay in English, is the largest bay in Madagascar. It is at the northern end of the east coast of the island and for administrative purposes it is within Analanjirofo Region. The bay is about 60 km long and 30 km wide, and is formed by...
, in the north down the coast to the Mananara River near Vangaindrano
Vangaindrano
Vangaindrano is a city in Atsimo-Atsinanana Region, Madagascar.The city is near the mouth of the Mananara river at the southern part of the east coast. It's connected to the north by national road RN 12. The road continues south but that section can't be used by ordinary vehicles, due to its bad...
in the south. Additionally, a concentrated population of black-and-white ruffed lemurs, of the subspecies Varecia variegata subcincta, can also be found on the island reserve of Nosy Mangabe
Nosy Mangabe
Nosy Mangabe is a small island reserve located in Antongil Bay about 2 km offshore from the town of Maroantsetra in eastern Madagascar. 520ha in size, it is accessible by small boat and is part of the larger Masoala National Park complex. It is a tropical rainforest preserve and sanctuary for...
in Antongil Bay. It is suspected that this population was introduced to the island in the 1930s. The red ruffed lemur, on the other hand, has a very restricted range on the Masoala Peninsula.
Historically, the confluence
Confluence
Confluence, in geography, describes the meeting of two or more bodies of water.Confluence may also refer to:* Confluence , a property of term rewriting systems...
of the Vohimara and Antainambalana Rivers may have been a zone of hybridization
Hybrid zone
A hybrid zone exists where the ranges of two interbreeding species meet. For a hybrid zone to be stable, the offspring produced by the cross have to be less fit than members of the parent species, although this condition does not need to be met in the very first hybrid generation...
between these two species, although no conclusive results have indicated current interbreeding. In general, the Antainambalana River appears to isolate
Reproductive isolation
The mechanisms of reproductive isolation or hybridization barriers are a collection of mechanisms, behaviors and physiological processes that prevent the members of two different species that cross or mate from producing offspring, or which ensure that any offspring that may be produced is not...
the red ruffed lemurs from the neighboring subspecies of black-and-white ruffed lemur, V. v. subcincta. The subspecies V. v. variegata can be found further south, and V. v. editorum is the southernmost subspecies. The ranges of these two southern subspecies overlap and intermediate forms are reported to exist, although this has not been confirmed.
The rainforests in which these animals live are seasonal, with two primary seasons: the hot, wet season (November through April), and the cool, dry season (May through October). The primary habitat for both species, at any season, is in the crowns of trees, where they spend the majority of their time 15 and 25 m (49.2 and 82 ft) above ground. With the seasonal availability of resources being similar regardless of location, there is little to no difference in tree usage between species. From September through April, more fruit is available, so females prefer the liana
Liana
A liana is any of various long-stemmed, woody vines that are rooted in the soil at ground level and use trees, as well as other means of vertical support, to climb up to the canopy to get access to well-lit areas of the forest. Lianas are especially characteristic of tropical moist deciduous...
s in the crowns of trees. Both sexes utilize the lower, major branches during the hot, rainy season. The tree crowns are predominantly used from May through August, when young leaves and flowers are in abundance.
Sympatric relations
The following lemur species can be found within the same geographic range as ruffed lemurs:- Greater dwarf lemur (Cheirogaleus major)Greater Dwarf LemurThe greater dwarf lemur , or the Geoffroy's dwarf lemur, is a lemur that is widely distributed over the primary and secondary forests near the eastern coast of Madagascar....
- Eastern lesser bamboo lemur (Hapalemur griseus griseus)
- Weasel sportive lemur (Lepilemur mustelinus)
- Diademed sifaka (Propithecus diadema)Diademed SifakaThe diademed sifaka , or diademed simpona, is an endangered species of sifaka, one of the lemurs endemic to certain rainforests in eastern Madagascar. This species is one of the world's largest living lemurs, with a total adult length of approximately 105 centimetres , half of which is tail...
- Common brown lemur (Eulemur fulvus)Common Brown LemurThe common brown lemur , or brown lemur, is a species of lemur in the Lemuridae family. It is found in Madagascar and Mayotte.-Range:...
- Red-bellied lemur (Eulemur rubriventer)Red-bellied LemurThe Red-bellied Lemur is a medium sized prosimian with a luxuriant chestnut brown coat. This lemur is endemic to eastern Madagascan rainforests and is distinguished by patches of white skin below the eyes, giving rise to a "teardrop" effect, particularly conspicuous in the male.The species, first...
- Eastern woolly lemur (Avahi laniger)Eastern Woolly LemurThe eastern woolly lemur , also known as the eastern avahi or Gmelin's woolly lemur, is a species of woolly lemur native to eastern Madagascar, where it lives in humid forests. This nocturnal animal weighs 1-1.3 kg and reaches a length of 27–29 cm with a tail of 33–37 cm...
- Indri (Indri indri)IndriThe indri , also called the babakoto, is one of the largest living lemurs. It is a diurnal tree-dweller related to the sifakas and, like all lemuroids, it is native to Madagascar.- Etymology :...
- Brown mouse lemur (Microcebus rufus)
- Aye-aye (Daubentonia madagascariensis)Aye-ayeThe aye-aye is a lemur, a strepsirrhine primate native to Madagascar that combines rodent-like teeth and a special thin middle finger to fill the same ecological niche as a woodpecker...
- White-headed lemur (Eulemur albifrons)White-headed LemurThe white-headed lemur , also known as the white-headed brown lemur, white-fronted brown lemur, or white-fronted lemur, is a species of primate in the Lemuridae family. It is only found in north-eastern Madagascar...
Ruffed lemurs either demonstrate feeding dominance or divide resources by using different forest strata. They are dominant over red-bellied lemurs, while eastern lesser bamboo lemurs avoid encountering them all together. White-headed lemurs, on the other hand, utilize the understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
and lower canopy, below 15 m (49.2 ft), while the ruffed lemurs utilize the upper canopy, above 15 m (49.2 ft). Play has even been observed between infant ruffed lemurs and White-headed Lemurs.
Behavior
Ruffed lemurs, on average, spend 28% of the day feeding, 53% resting, and 19% traveling, although differences in resting and feeding durations have been observed between males and females, with females resting less and feeding more. They are diurnal; although peak activity occurs during the early morning and late afternoon or evening, resting usually occurs around midday. When resting, ruffed lemurs often sit hunched or upright. They are also frequently seen lying proneProne position
The term means to lie on bed or ground in a position with chest downwards and back upwards.-Etymology :The word "prone," meaning "naturally inclined to something, apt, liable," has been recorded in English since 1382; the meaning "lying face-down" was first recorded in 1578, but is also referred to...
over a branch or sunbathing in a supine position
Supine position
The supine position is a position of the body: lying down with the face up, as opposed to the prone position, which is face down, sometimes with the hands behind the head or neck. When used in surgical procedures, it allows access to the peritoneal, thoracic and pericardial regions; as well as the...
with the limbs outstretched. When feeding, they will often hang upside-down by their hind feet, a type of suspensory behavior
Suspensory behavior
Suspensory Behavior, exhibited by primates, is a form of arboreal locomotion or a feeding behavior which involves hanging or suspension of the body below or among the branches, rather than moving or sitting on top of the branches...
, which allows them to reach fruits and flowers.
Being highly arboreal, they spend the majority of their time in the high canopy throughout the day. Ruffed lemurs spend the majority of their time between 15 to 20 m (49.2 to 65.6 ft) above the forest floor, followed by 20 to 25 m (65.6 to 82 ft) up, and are least frequently seen at 10 to 15 m (32.8 to 49.2 ft). During the hot season, they will relocate to the lower canopy to help regulate their body temperature. In the cold season, ruffed lemurs are least active and may dedicate 2% of their resting time to sunbathing in order to warm up.
Long-term field research has shown that range size, group size, social systems, and territorial behavior vary widely, and may be greatly affected by food distribution and quality. It is generally agreed that the ruffed lemur social system is multi-male/multi-female with a fission-fusion society
Fission-fusion society
In primatology, a fission-fusion society is one in which the social group, e.g. bonobo collectives of 100-strong, sleep in one locality together, but forage in small groups going off in different directions during the day. This form of social organization occurs in several other species of...
, although some populations of black-and-white ruffed lemur have been reported as monogamous. This social flexibility is suspected to improve survivability despite an inflexible feeding ecology.
Diet
Being the most frugivorousFrugivore
A frugivore is a fruit eater. It can be any type of herbivore or omnivore where fruit is a preferred food type. Because approximately 20% of all mammalian herbivores also eat fruit, frugivory is considered to be common among mammals. Since frugivores eat a lot of fruit they are highly dependent...
members of the family Lemuridae, consuming an average of 74–90% fruit, ruffed lemurs also consume nectar (4–21%), and supplement the rest of their diet with young leaves (3–6%), mature leaves (1%), flowers (3–6%), and some seeds. Ruffed lemurs have also been reported to come to the ground to eat fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
and exhibit geophagy
Geophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
.
The majority of their diet is made up of relatively few common plant species, with a few species providing more than 50% of the diet. Fig species of the genus Ficus
Ficus
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...
, for example, account for 78% of the fruit consumed by red ruffed lemurs on the Masoala Peninsula. Although plant species and diets vary by location, the most common food plants reported from the field include the following:
- CanariumCanariumCanarium is a genus of about 75 species of tropical and subtropical trees in the family Burseraceae, native to tropical Africa, southern Asia, and Australia, from southern Nigeria east to Madagascar, Mauritius, India, southern China, Indonesia and the Philippines...
- CryptocaryaCryptocaryaCryptocarya is a genus of evergreen trees belonging to the Laurel family, Lauraceae. The genus includes more than 350 species, distributed through the Neotropic, Afrotropic, Indomalaya, and Australasia ecozones.-Overview:...
- OcoteaOcoteaOcotea is a genus of flowering plants belonging to the family Lauraceae. The genus includes over 200 species of evergreen trees and shrubs, distributed mostly in tropical and subtropical regions of Central and South America, the West Indies, also with a few species in Africa and Madagascar, and...
- RavensaraRavensaraThe Ravensara is a Madagascar endemic genus of trees and shrubs flowering plants belonging to the family Lauraceae. Ravensare species produce Essential Oils from their bark, their leaves and their fruit....
(family LauraceaeLauraceaeThe Lauraceae or Laurel family comprises a group of flowering plants included in the order Laurales. The family contains about 55 genera and over 3500, perhaps as many as 4000, species world-wide, mostly from warm or tropical regions, especially Southeast Asia and South America...
) - FicusFicusFicus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...
- EugeniaEugeniaEugenia is a genus of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven, distribution in tropical and subtropical regions. The bulk of the approximately 1,000 species occur in the New World tropics, especially in the northern Andes, the Caribbean, and the...
/SyzygiumSyzygiumSyzygium is a genus of flowering plants that belongs to the myrtle family, Myrtaceae. The genus comprises about 1100 species, and has a native range that extends from Africa and Madagascar through southern Asia east through the Pacific... - GrewiaGrewiaThe large flowering plant genus Grewia is today placed by most authors in the mallow family Malvaceae, in the expanded sense as proposed by in the APG. Formerly, it was placed in either the linden family or the Sparrmanniaceae...
Fruit trees do not appear to be selected by species, but by availability and accessibility of edible fruit. And despite predominance of a few plant species in the ruffed lemur diet, the remainder of their diet consists of between 80 and 132 other species from 36 plant families.
The availability of food reflects the seasonal nature of the forests in which they live. During the hot season, fruit, flowers, and young leaves are more abundant, whereas the cold, wet season offers more young leaves and flowers. Despite this, the diet changes little between seasons, except that females will consume more high-protein, low-fiber items, such as young leaves and flowers, during pregnancy and lactation in order to offset the energy costs of reproduction. Nectar is only available sporadically, yet constitutes a major food source when the flowers bloom. The nectar of the traveller's palm (Ravenala madagascariensis) is a favorite among ruffed lemurs.
Social systems
The social organization of ruffed lemurs is widely variable in both group organization and group composition, although no notable difference can be seen between the two species. Ruffed lemurs are typically described as multi-male groupMulti-male group
Multi-male groups, also known as multi-male/multi-female, are a type of social organization where the group contains more than one adult male, more than one adult female, and offspring of all ages. Within Order Primates, it is the most common social group type, with group sizes ranging from 10 to...
s with a fission-fusion
Fission-fusion society
In primatology, a fission-fusion society is one in which the social group, e.g. bonobo collectives of 100-strong, sleep in one locality together, but forage in small groups going off in different directions during the day. This form of social organization occurs in several other species of...
social structure, although this can vary by season and locality.
In a study done at Masoala Peninsula on red ruffed lemurs three levels of organization were identified and defined: communities, core groups, and subgroups. Communities are individuals that affiliated regularly with each other, but rarely with conspecifics
Conspecificity
Conspecificity is a concept in biology. Two or more individual organisms, populations, or taxa are conspecific if they belong to the same species....
outside of the community. Although the entire multi-male/multi-female community lives within a discrete home range, all individuals are never seen in the same location at the same time. Instead, individuals form dispersed social networks, known as core groups, within the community. Core groups are individuals that shared the same core area within a community territory throughout the year. Core groups typically consist of two reproductive females, as well as reproductive males and subadults, ranging in size from two individuals to nine. Females within the groups are cooperative, but male encounters are often agonistic. Subgroups, on the other hand, vary daily in size, composition, and duration, and consist of associated individuals from either the same core group or different core groups, depending on the season. It is from the consistent, daily changes in these subgroups that occur throughout the year, as well as the seasonal formations of core groups in core areas, that demonstrate the fission-fusion nature of ruffed lemur social structure.
Nosy Mangabe
Nosy Mangabe is a small island reserve located in Antongil Bay about 2 km offshore from the town of Maroantsetra in eastern Madagascar. 520ha in size, it is accessible by small boat and is part of the larger Masoala National Park complex. It is a tropical rainforest preserve and sanctuary for...
on black-and-white ruffed lemurs a fourth level or organization was defined: affiliates. Affiliates were individuals with more persistent social bonds and more frequent interactions, usually within a core group, but sometimes also between core groups within a subgroup. Adult females typically had many affiliates, whereas adult males rarely interacted with conspecifics, living a more solitary existence.
Past studies have reported other social organizations in ruffed lemurs including monogamous
Monogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
pair bonding. This may have been due to the use of short-term, seasonal field studies instead of yearlong studies that take into consideration the effects that changing seasons have on ruffed lemur communities. For instance, during the cold, rainy season, which corresponds with the breeding season, interactions between core groups within a community are significantly reduced. During this time small subgroups form consisting of a mature female, a mature male, and sometimes offspring. This can be misinterpreted as monogamous pair bonding.
Ranging behavior can also exhibit seasonal variability. During the hot, wet season, females range widely, either alone or in groups of up to six individuals. In the cool, dry season, smaller core groups stabilize in order to occupy concentrated areas. Therefore, during seasons when fruit is abundant, subgroups are larger while scarcity is met with more solitary behavior. This suggests that although their feeding ecology is inflexible, being tied to widely distributed, patchy, and sometimes scarce fruit, ruffed lemurs instead adapt the social system in order to survive.
In terms of dominance, the ruffed lemur's social structure is not as clear-cut as other lemur societies where female dominance
Matriarchy
A matriarchy is a society in which females, especially mothers, have the central roles of political leadership and moral authority. It is also sometimes called a gynocratic or gynocentric society....
is the norm. Although it is historically reported that "males were subordinate to females," especially with captive and free-ranging ruffed lemur populations demonstrating this, wild populations cannot be definitively labeled as matriarchal
Matriarchy
A matriarchy is a society in which females, especially mothers, have the central roles of political leadership and moral authority. It is also sometimes called a gynocratic or gynocentric society....
due to inter-group variation.
There are also social differences between males and females. Females typically have many affiliates and bond strongly with other females both within and outside their core areas, but do not affiliate with individuals outside the community range, except during mating season. Males, on the other hand, are more solitary, interact with only a couple of conspecifics, have weak social bonds with other males, and rarely associate with others outside their core group. Furthermore, field studies suggest that only females play a role in communal home range defense. Males may scent-mark and remain relatively silent, but otherwise show little involvement during disputes.
Community range or territory
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
size can vary widely, from 16 ha (0.16 km²; 0.0617763453748056 sq mi) while group size can range from a single pair to 31 individuals. Population density
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...
is also noticeably variable. These wide ranges can be attributed to differing levels of protection and degree of environmental degradation, with better protection and a less degraded environment resulting in higher population density and more moderately sized community ranges. (The duration and seasonality of the studies involved may also have contributed to low group size estimates and community ranges. A study at the Betampona Reserve
Betampona Reserve
Betampona Reserve is a nature reserve in Toamasina Province of Madagascar. It is located 40 km northwest of Toamasina and was established in 1927. The area of the reserve is 29.2 km².-References:**...
, for instance, observed monogamous pairs with two to five infants maintaining ranges of 16 ha (0.16 km²; 0.0617763453748056 sq mi).) Core areas at Ambatonikonilahy
Ambatonikonilahy
Ambatonikonilahy is a town and commune in Madagascar. It belongs to the district of Betafo, which is a part of Vakinankaratra Region. The population of the commune was estimated to be approximately 18,000 in 2001 commune census....
constituted approximately 10% of the overall community range and showed a close relationship with the location of the largest fruiting trees.
The average daily traveling distance for ruffed lemurs varies between 436 to 2250 m (1,430.4 to 7,381.9 ft), averaging 1129 metres (3,704.1 ft) per day. Activity patterns within the community range vary by gender and season. Males generally stay within a core area all year, whereas females only confine themselves to a core area during the cold wet season, then expand their range throughout the community range during the hot, rainy season. Females expand their traveling range slightly after giving birth, still staying within the core area, but gradually range further in December when they begin stashing their infants with other community members while they look for food. Females range the furthest later during the hot, rainy season. Both activity level and reproductive activity can be summarized in the following table.
| Season | Months | Stage | Reproductive cycle | Females activity | Male activity |
|---|---|---|---|---|---|
| hot, rainy season | November – April | early | Infant rearing | Expanding travel & infant stashing | Remains in core area |
| late | Infant rearing | Expands travel throughout community range | Remains in core area | ||
| cool, dry season | May – October | early | Mating season | Remains in core area | Remains in core area |
| late | Gestation and birth | Remains in core area & nest building | Remains in core area |
Although males demonstrate little involvement in territorial disputes between neighboring communities, and ruffed lemur communities lack cohesiveness, females communally defend the community range against females of other communities. These disputes occur mostly during the hot, rainy season, when resources are more abundant and occur near the boundaries of community ranges. Spacing is maintained by scent marking and vocal communication. Ruffed lemurs are known for their loud, raucous calls that are answered by neighboring communities and subgroups within the same community.
During agonistic encounters between communities, chasing, scent-marking, calling, and occasional physical contact can be seen. Other social behaviors appear to vary between wild and captive ruffed lemurs, as illustrated by the following table.
| Wild behaviors | Captive behaviors | |
|---|---|---|
| Aggressive/Agonistic behaviors |
|
|
| Submissive behaviors |
|
|
| Affiliate/Affinitive behaviors |
|
|
Some affiliative behaviors are seasonal or gender-specific, such as the male squeal approach and anogenital inspections performed during the mating season. Another example is the female greeting behavior, where two females will use their anogenital scent glands to mark each other's backs, jump over one another, writhe together, and emit squealing vocalizations. This behavior is not seen during the end of the cool, dry season or around gestation. The frequency of other affiliative behaviors can be affected by age. All ruffed lemurs over five months of age allogroom
Social grooming
In social animals, including humans, social grooming or allogrooming is an activity in which individuals in a group clean or maintain one another's body or appearance. It is a major social activity, and a means by which animals who live in proximity can bond and reinforce social structures, family...
, and, in captivity, subadults participate in play more frequently than adults.
Cognitive abilities
Historically, relatively few studies of learningLearning
Learning is acquiring new or modifying existing knowledge, behaviors, skills, values, or preferences and may involve synthesizing different types of information. The ability to learn is possessed by humans, animals and some machines. Progress over time tends to follow learning curves.Human learning...
and cognition
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...
have been performed on strepsirrhine primates, including ruffed lemurs. However, a study at the Myakka City Lemur Reserve demonstrated that ruffed lemurs, along with several other members of the family Lemuridae, could understand the outcome of simple arithmetic operations.
Olfactory communication
As with all prosimianProsimian
Prosimians are a grouping of mammals defined as being primates, but not monkeys or apes. They include, among others, lemurs, bushbabies, and tarsiers. They are considered to have characteristics that are more primitive than those of monkeys and apes. Prosimians are the only primates native to...
primates, olfactory
Olfaction
Olfaction is the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates...
communication is used extensively by ruffed lemurs – scent marking in territorial defense and disputes, as well as female greeting displays. The scents communicate the sex, location, and identity of their owner.
Females predominantly scent mark with their anogenital scent gland
Scent gland
Scent glands are found in the genital area of most mammals and in various other parts of the body, such as the underarms of humans and the preorbital glands of deer and muskox. They produce a semi-viscous fluid which contains pheromones. These odor-messengers indicate information such as status,...
s, by squatting to rub their anogenital region along horizontal surfaces, such as tree limbs. Males, on the other hand, favor using the glands on their neck, muzzle, and chest, by embracing horizontal and vertical surfaces and rubbing themselves over them. Both sexes will occasionally scent mark in ways characteristic of the opposite sex.
In greeting displays, female ruffed lemurs will leap over one another, scent marking the other individual's back in the process.
Auditory communication
Ruffed lemurs are highly vocal, with an extensive vocal repertoire with calls being used in multiple contexts. Calls can also vary seasonally. During the hot, rainy season, the loud, raucous calls that are a hallmark of ruffed lemurs allow groups to remain in contact and maintain spacing. These loud calls can be heard up to 1 kilometre (0.621372736649807 mi) away.Ruffed lemurs utilize alarm calls that differentiate between ground and aerial predators. For instance an abrupt roar or huff alerts the group to an avian predator, and a pulsed squawk or growl-snort communicates the existence of a mammalian ground predator. When sounding these calls, such as the pulsed squawk, adults direct them at the predator after moving to a safe position. Once the alarm call is sounded by one individual, the resulting chorus can even reach the furthest ranging community members.
In captivity, ruffed lemur vocalizations have been studied and divided into three general groups: high-, medium-, and low-amplitude calls.
| Call | Inferred Function |
|---|---|
| Roar/shriek chorus |
|
| Abrupt roar |
|
| Pulsed squawk |
|
| Wail
(V. variegata only) |
|
| Bray |
|
| Quack |
|
The well-known roar/shriek chorus is spontaneous, occurring most often during period of high activity, as well as being contagious, involving communal participation including infants three to four months old. Abrupt roars are also more common during high activity and aside from alerting group members to the presence of an avian predator, they probably also help maintain contact with individuals outside of visual range or indicate an aggressive/defensive response to a disturbance. In the wild, both of these calls are emitted more during the hot, rainy season due to heighten activity. All high-amplitude calls are delivered with from a "taut" body posture.
| Call | Inferred Function |
|---|---|
| Growl |
|
| Growl-snort |
|
| Chatter |
|
| Whine
|
|
Medium-amplitude calls operate over a shorter range or often involve moderately arousing situations, such as frustration or submission. Low-amplitude calls also generally operate over a short range, yet also cover a wider range of aggravation levels.
Whines are highly variable between individual ruffed lemurs. Cough, grumble, squeak, and squeal have only been observed and researched in the wild.
| Call | Inferred Function |
|---|---|
| Grunt |
|
| Huff
|
|
| Mew
|
|
| Cough |
|
| Grumble |
|
| Squeak |
|
| Squeal |
|
The calls of ruffed lemurs vary only slightly between the two species. In fact, in captivity, it has been documented that red ruffed lemurs understand and even join in the alarm calls of black-and-white ruffed lemurs. One minor difference between the vocal repertoires of these two species is in the pulse rate and frequency of the pulsed squawk, which is much faster and higher in red ruffed lemurs than in black-and-white ruffed lemurs. The difference in this vocalization is only interspecific, showing no signs of significant sexual dimorphism within each species.
Red ruffed lemurs do not appear to produce a bona fide wail vocalization. In black-and-white ruffed lemurs, pulsed squawks sometimes slow down as the group calms down, and integrate with the wail, creating pulsed squawk-wail intermediates . red ruffed lemurs also produce pulsed squawk-wail intermediate sounds, but they do not exhibit long, drawn-out wails like the black-and-white ruffed lemurs.
Breeding and reproduction
Contrary to initial reports of monogamy, ruffed lemurs in the wild exhibit seasonal polygamous breeding behavior, with both males and females mating with more than one partner within a single season. Mating is not restricted to just community members, but also involves members of neighboring communities. Females mate primarily with males with whom they had affiliative relations prior to mating season, although some matings occurred with roaming males from other communities.Shortly before mating season begins, females exhibit swelling of the sex skin, which reaches its peak around the middle of their 14.8 day estrous cycle
Estrous cycle
The estrous cycle comprises the recurring physiologic changes that are induced by reproductive hormones in most mammalian placental females. Estrous cycles start after puberty in sexually mature females and are interrupted by anestrous phases or pregnancies...
. Male sexual physiology also undergoes its own change, with testicular volume increasing during mating season, peaking around the time of breeding. Aggression also increases during the mating season, both between members of the same sex and by females towards the male attempting to mate with her. Females have been observed grappling, cuffing, and biting the male during copulation
Sexual intercourse
Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails...
. Either sex may approach the other when the female is in estrus. Initially they may roar-shriek with each other. When a male approaches a female he often lowers his head and squeals, inspecting the female's genitalia by licking or sniffing, scent-marking, and offering a submissive chattering vocalization. When a female approaches a male, she may posture herself for mounting. Mating pairs often copulate many times during the course of a mating bout.
The mating season lasts from May through July, during the cold, rainy season, resulting in birth and peak lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...
coinciding with the time that fruit is the most plentiful. The gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period of ruffed lemurs is the shortest of the family Lemuridae, averaging 102 days (with a range of 90 to 106 days). Gestation in the wild last slightly longer than in captivity, averaging 106 days. Just like the mating season, parturition is also seasonal, synchronized to the end of the cold, dry season and the start of the productive hot, rainy season.
In addition to an abnormally short gestation period, ruffed lemurs share another feature with small, nocturnal lemurs by producing the largest litters
Litter (animal)
A litter is the offspring at one birth of animals from the same mother and usually from one set of parents. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from...
of the family Lemuridae. Litters typically include two or three infants, although up to five have been reported. Birth weights in captivity average between 83 to 101.7 g (2.9 to 3.6 oz) and range from 70 to 140 g (2.5 to 4.9 oz). Ruffed lemur infants are altricial
Altricial
Altricial, meaning "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born...
, and are born with their eyes open and a full coat of fur.
Unlike other diurnal primates, which usually carry their infants with them, ruffed lemur mothers will stash their young by concealing them in the canopy foliage, leaving them to rest and sit quietly for several hours while she forages and performs other activities. Mothers continue to transport their offspring by mouth, moving them one at a time by grasping the infant's belly crosswise. This form of transport usually stops around 2.5 months of age when the infants become too heavy to carry.
Ruffed lemurs are cooperative breeders
Cooperative breeding
Cooperative breeding is a social system in which individuals contribute care to offspring that are not their own at the expense of their own reproduction . When reproduction is monopolized by one or few of the adult group members and most adults do not reproduce, but help rear the breeder’s...
, with parental care being shared by all community members. For example, mothers will stash their offspring with other mothers or leave them to be guarded by other community members, including non-breeding individuals of both genders. While the mother is away, community members will not only care for and guard them, but also sound alarm calls if danger is detected or if leaving the infant alone. They will also respond to alarm calls by others. These coordinated vigilance displays further involve communal transmission of the alarm call, with nearby community members repeating the alarm call, potentially summoning the mother back to her offspring. Infant transport by other members of the community has also been recorded. Females have been observed nursing infants of their close relatives, while close kin have adopted rejected infants, acting as foster parents.
Male care for infants has been documented in ruffed lemur societies. During early development, adult males may guard the nests of multiple core group females, as well as help care for the infants that were likely fathered by other males. During the season when females practice infant stashing, males effectively lighten the reproductive burden of up to several mothers by guarding, huddling, grooming, travelling, playing with and feeding the young.
Female ruffed lemurs produce relatively rich milk compared to other lemurs, and consequently, their young develop faster than those of other lemurs. Infants develop rapidly, attaining approximately 70–75% adult weight by the age of four months. They begin climbing and clinging at one month of age, advancing to the point of independently following their mother and group members through the canopy at heights of 50 to 100 m (164 to 328.1 ft) by two to three months. Full adult mobility is attained at three to four months of age. Socially, they begin exchanging contact calls with their mother at three weeks, and select their mother as their play partner 75–80% of the time during the first three months. Participation in greeting displays and utilization of more extensive vocalizations commences around four months, while scent marking does not start until six months of age. Infants begin testing solid food starting around 40 days to two months with weaning occurring between four to six months in the wild, although some individuals have continued to nurse until seven to eight months.
Infant mortality is often high among ruffed lemurs, but can also be highly variable. In some seasons, as many as 65% are unable to reach three months of age, possibly due to falls and related injuries, although in some seasons infant mortality is as low as 0%. For those that do survive to adulthood, sexual maturity is attained at 18 to 20 months in females and 32 to 48 months in males. Sexual maturity may take longer to reach in the wild compared to captivity. For females, the inter-birth interval, or time between successive offspring, is typically one year, and in captivity, females can remain reproductively active until the age of 23. The life expectancy for both species of ruffed lemur is estimated at 36 years in captivity, although it is likely to be considerably less in the wild.
Conservation status
In a land where approximately 90% of the original island forest has been destroyed, ruffed lemurs cling to only a small fraction of their original range. Completely dependent upon large fruiting trees, neither species appears to be flexible with its habitat choice, with selective loggingSelection cutting
Selection cutting is the silvicultural practice of harvesting a proportion of the trees in a stand. Selection cutting is the practice of removing mature timber or the lessening of older trees to improve the timber stand. This system may be used to manage even or uneven-aged stands...
resulting in significantly lower population densities
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...
. Although they can survive in very disturbed habitats with lower population densities, they are still especially vulnerable to habitat disturbance. Decreased genetic diversity, in tandem with hunting, natural disasters, predation, and disease, can easily wipe out small populations.
The black-and-white ruffed lemur
Black-and-white ruffed lemur
The black-and-white ruffed lemur is the more endangered of the two species of ruffed lemurs, both of which are endemic to the island of Madagascar. Despite having a larger range than the red ruffed lemur, it has a much smaller population that is spread out, living in lower population densities...
was elevated by the IUCN to Critically Endangered (A2cd) status from Endangered status in 2008. They cite that "the species is believed to have undergone a decline of 80% over a period of 27 years, due primarily to a decline in area and quality of habitat within the known range of the species and due to levels of exploitation." The total area of all known localities in which black-and-white ruffed lemurs exist is estimated at less than 8000 km² (3,088.8 sq mi), while the total wild population is estimated between 1,000 and 10,000.
The red ruffed lemur
Red Ruffed Lemur
The red ruffed lemur is one of two species in the genus Varecia, the ruffed lemurs; the other is the black-and-white ruffed lemur . Like all lemurs, it is native to Madagascar and occurs only in the rainforests of Masoala, in the northeast of the island...
was downgraded to Endangered status from Critically Endangered status by the IUCN in 2008. The justification given includes its limited range, its restriction to only the Masoala Peninsula, and its risk from ongoing habitat loss and hunting. This species occupies a range of no more than 4000 km² (1,544.4 sq mi), while the total wild population is estimated between 29,000 and 52,000 individuals. Red ruffed lemurs are only protected within the boundaries of the Masoala National Park
Masoala National Park
Masoala National Park, in northeast Madagascar, is the largest of the island's protected areas. Most of the park is situated in Sava Region and a part in Analanjirofo. Created in 1997, the park protects 2,300 square kilometres of rainforest and 100 square kilometres of marine parks. The Masoala...
. Historically, this species has been considered more threatened due to its highly restricted range, compared to the widely distributed black-and-white ruffed lemur. However, its protection within the island's largest national park has slightly improved its chances at survival.
There are several organizations involved in ruffed lemur conservation, including the Durrell Wildlife Conservation Trust
Durrell Wildlife Conservation Trust
Durrell Wildlife Conservation Trust is a conservation organisation with a mission to save species from extinction.Gerald Durrell founded the Jersey Wildlife Preservation Trust as a charitable institution in 1963 with the Dodo as its symbol...
, the Lemur Conservation Foundation (LCF)
Lemur Conservation Foundation
The Lemur Conservation Foundation is a small American non-profit organization that works closely with the Duke Lemur Center, LCF Scientific Advisory Council , the Association of Zoos and Aquariums Prosimian Taxon Advisory Group , and the Species Survival Plan coordinators...
, the Madagascar Fauna Group (MFG)
Madagascar Fauna Group
The Madagascar Fauna Group or MFG is an international consortium of zoos and other conservation agencies which pool together resources to help conserve animal species in Madagascar, through captive breeding programs, field research programs, training programs for rangers and wardens, and...
, Monkeyland Primate Sanctuary in South Africa, Wildlife Trust
Wildlife Trust (US)
EcoHealth Alliance, formerly known as Wildlife Trust, is a non-profit, non-governmental organization headquartered in New York City working on conservation ecology and issues in the United States and around the world....
, and the Duke Lemur Center (DLC)
Duke Lemur Center
The Duke Lemur Center is an sanctuary for rare and endangered prosimian primates, located at Duke University in Durham, North Carolina. It is the largest sanctuary for prosimian primates in the world....
. To conservation organizations, the ruffed lemurs are considered indicator
Indicator species
An indicator species is any biological species that defines a trait or characteristic of the environment. For example, a species may delineate an ecoregion or indicate an environmental condition such as a disease outbreak, pollution, species competition or climate change...
, umbrella
Umbrella species
Umbrella species are species selected for making conservation related decisions, typically because protecting these species indirectly protects the many other species that make up the ecological community of its habitat. Species conservation can be subjective because it is hard to determine the...
, and flagship species
Flagship species
The concept of flagship species is a surrogate species concept with its genesis in the field of conservation biology. The flagship species concept holds that by raising the profile of a particular species, it can successfully leverage more support for biodiversity conservation at large in a...
.
Threats in the wild
As with other primates, one of the principal threats to both ruffed lemur species is habitat loss due to slash-and-burn agriculture, loggingLogging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
, and mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
. Both species appear to be very sensitive to logging, and are thought to be the most vulnerable of rainforest lemurs. The hardwood
Hardwood
Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...
s that are favored for construction materials and selectively logged are also preferred by ruffed lemurs for their fruits and potentially affect their travel routes through the canopy. Deforestation
Deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
, on the other hand, is a result of the need to provide firewood and to support subsistence agriculture
Subsistence agriculture
Subsistence agriculture is self-sufficiency farming in which the farmers focus on growing enough food to feed their families. The typical subsistence farm has a range of crops and animals needed by the family to eat and clothe themselves during the year. Planting decisions are made with an eye...
and cash crop
Cash crop
In agriculture, a cash crop is a crop which is grown for profit.The term is used to differentiate from subsistence crops, which are those fed to the producer's own livestock or grown as food for the producer's family...
s. For red ruffed lemurs, Slash-and-burn agriculture, known locally as tavy, is practiced seasonally on the Masoala peninsula between October and December, and its practice is expanding. Additionally, cattle are sometimes allowed to free-range over these former agricultural clearings, preventing forest re-growth.
Another principal threat to the survival of ruffed lemurs is hunting. Local human populations still hunt and trap ruffed lemurs with traditional weapons, using them as a source of subsistence. Studies from villages in the Makira Forest have revealed that ruffed lemur meat is not only a desired food, but is being hunted unsustainably. On the Masoala peninsula, the calls of red ruffed lemurs help hunters locate them. On this peninsula, firearms are used in addition to traditional traps, known as laly, which involve a 5 metres (16.4 ft) strip of cleared forest with snares set on the few remaining branches that allow the lemurs to cross. Although hunting is illegal, the laws are generally not enforced and the local inhabitants show little concern about their hunting practices, which occur mostly from May to September. Hunting is the biggest concern in the Masoala peninsula because it is likely to continue, whereas logging and slash-and-burn agriculture could be curtailed. In other regions, hunters can scare away ruffed lemurs from their favorite food sources, even if they are hunting other prey. Lastly, these animals are taken from their natural habitats to display for tourists or are sold as exotic pet
Exotic pet
An exotic pet is a rare or unusual animal pet, or an animal kept as a pet which is not commonly thought of as a pet.The definition is an evolving one; some rodents, reptiles, and amphibians have become firmly enough established in the world of animal fancy to no longer be considered exotic...
s.
Frequent cyclone
Cyclone
In meteorology, a cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth. This is usually characterized by inward spiraling winds that rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale...
s also pose a threat, particularly to concentrated or small populations. In late January 1997, cyclone Gretelle destroyed 80% of the Manombo forest canopy. With their habitat, including most of their food resources, effectively destroyed, the ruffed lemurs of the forest broadened their diet, remaining surprisingly frugivorous. Their body weights dropped and no births were reported for four years, but they managed to stave off starvation. This event demonstrated not only their flexibility in the face of natural disasters, which may highlight the evolutionary reasons behind their reproductive capacity and litter size, but also the threat faced by already stressed populations.
Predation in the wild appears to be very rare for ruffed lemurs, probably because living in the high canopy makes them challenging to catch. Evidence of predation by raptors, such as the Henst's goshawk
Henst's Goshawk
Henst's Goshawk is a species of bird of prey in the Accipitridae family.It is endemic to Madagascar. Its natural habitats are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, subtropical or tropical moist montane forests, and plantations.It is threatened by...
(Accipiter henstii) suggests it occurs at a low rate. The fossa
Fossa (animal)
The fossa is a cat-like, carnivorous mammal that is endemic to Madagascar. It is a member of the Eupleridae, a family of carnivorans closely related to the mongoose family . Its classification has been controversial because its physical traits resemble those of cats, yet other traits suggest a...
(Cryptoprocta ferox) could present a potential risk if it found an individual lower in the forest canopy, but no confirmation has been presented to indicate that they prey upon ruffed lemurs. Instead, only re-introduced, captive-bred ruffed lemurs have been killed by fossa, likely due to their inexperience with predators. Nesting behavior poses the biggest risk of predation, making them susceptible to carnivorous mammals, such as the ring-tailed mongoose
Ring-tailed mongoose
The Ring-tailed mongoose is a euplerid that lives on the island of Madagascar. There is actually much disagreement about the placement of Madagascar's carnivores including the Ring-tailed mongoose, within the phylogenetic tree. Recent molecular work by Anne Yoder et al...
(Galidia elegans) and brown-tailed mongoose
Brown-tailed Mongoose
The brown-tailed mongoose, Malagasy brown-tailed mongoose, or salano is a species of mammal in the Eupleridae family. It is endemic to Madagascar. Its natural habitat is subtropical or tropical dry forests...
(Salanoia concolor).
Captive breeding and reintroductions
Captive populations of both ruffed lemur species exist in American and European zoos, representing a safeguard against extinction. In the United States, captive breedingCaptive breeding
Captive breedingis the process of breeding animals in human controlled environments with restricted settings, such as wildlife reserves, zoos and other conservation facilities; sometimes the process is construed to include release of individual organisms to the wild, when there is sufficient...
is managed by the Species Survival Plan (SSP)
Species Survival Plan
The American Species Survival Plan or SSP program was developed in 1981 by the Association of Zoos and Aquariums to help ensure the survival of selected species in zoos and aquariums, most of which are threatened or endangered in the wild....
, a program developed by the Association of Zoos and Aquariums (AZA)
Association of Zoos and Aquariums
The Association of Zoos and Aquariums was founded in 1924 and is a nonprofit organization dedicated to the advancement of zoos and public aquariums in the areas of conservation, education, science, and recreation.The AZA headquarters is located in Silver...
. Although the populations are very limited in their genetic diversity, these species thrive in captivity, making them an ideal candidate for reintroduction
Reintroduction
Reintroduction is the deliberate release of a species into the wild in zones formerly inhabited by said species but where it has disappeared from for a number of reasons, from captivity or relocated from other areas where the species still survives in...
into protected habitat, if it is available. Although reintroduction is seen as a last resort among conservationists
Conservation movement
The conservation movement, also known as nature conservation, is a political, environmental and a social movement that seeks to protect natural resources including animal, fungus and plant species as well as their habitat for the future....
, a combination of in situ conservation efforts, such as legal protection, public education, the spread of sustainable livelihoods
Sustainability
Sustainability is the capacity to endure. For humans, sustainability is the long-term maintenance of well being, which has environmental, economic, and social dimensions, and encompasses the concept of union, an interdependent relationship and mutual responsible position with all living and non...
, and reforestation
Reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....
offer hope for ruffed lemurs. In the meantime, reintroductions offer conservation research opportunities and allow the limited genetic diversity maintained by the SSP to improve the genetic diversity of dwindling Malagasy ruffed lemur populations.
A captive release first occurred in November 1997, when five black-and-white ruffed lemurs (Varecia variegata variegata) born in the United States were returned to Madagascar for release in the Betampona Strict Nature Reserve
Betampona Reserve
Betampona Reserve is a nature reserve in Toamasina Province of Madagascar. It is located 40 km northwest of Toamasina and was established in 1927. The area of the reserve is 29.2 km².-References:**...
in eastern Madagascar. Popularly known as the Carolina Five, these individuals had lived their entire lives in the Natural Habitat Enclosures at the Duke Lemur Center (DLC). Since then, two more groups totaling 13 captive-born ruffed lemurs have been reintroduced into the same reserve, once in November 1998 and again in January 2001. These latter two groups also received "boot camp training" in the DLC forested free-range enclosures prior to release. So far, the results have shown some success, with 10 surviving longer than one year, 3 individuals integrating into wild groups, and 4 offspring have been born to or sired by released lemurs, all of which were parent-raised. Saraph, a male released with the first group, was reported to be doing well seven years post-release, living in a social group with a wild female and their offspring. Research has been ongoing since the initial release, as illustrated in the 1998 BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
documentary In the Wild: Operation Lemur with John Cleese
John Cleese
John Marwood Cleese is an English actor, comedian, writer, and film producer. He achieved success at the Edinburgh Festival Fringe and as a scriptwriter and performer on The Frost Report...
. The research has provided useful information about their adaptation to life in the wild.
External links
- Ruffed lemur skeleton – Skeleton from the University of Texas at Austin
- Research on Red-ruffed lemur
- Primate Info Net Varecia Factsheet
- Parco Zoo Punta Verde The black and white ruffed lemur—Varecia variegata
- San Francisco Zoo Animals Descriptions
- The Wild Ones Animal Index
- Information on Endangered Mammals