Atlantic Titi
Encyclopedia
The Atlantic titi or masked titi, Callicebus personatus, is a species of titi
Titi
The titis, or titi monkeys, are the New World monkeys of the genus Callicebus. They are the only extant members of the Callicebinae subfamily, which also contains the extinct genera Xenothrix, Antillothrix, Paralouatta, Carlocebus, Homunculus, Lagonimico and possibly also Tremacebus.Titis live in...

, a type of New World monkey
New World monkey
New World monkeys are the five families of primates that are found in Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Platyrrhini parvorder and the Ceboidea superfamily, which are essentially synonymous since...

, endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...

 to Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

.

Distribution and general features

The Atlantic titi is part of the genus Callicebus which is composed of thirteen species and sixteen subspecies. More specifically, they belong to the group Callicebus moloch which is composed of eight species and eight subspecies. Three subspecies of Callicebus personatus have been described in scientific literature: C.p. melanochir, C.p. nigrifrons, and C.p. personatus. These three subspecies are products of clinical differentiation (when certain portions of the population are cut off from the parental stock due to an ecological barrier such as a river and are thus completely genetically isolated from one another). Atlantic Titis are territorial, middle-sized, cebid monkeys; usually 1-2 kg in size. C. personatus are found primarily in the humid forests east of the Andes Mountains, specifically in the coastal, inland forests of south-eastern Brazil. The states they have been documented to dwell within include Bahia
Bahia
Bahia is one of the 26 states of Brazil, and is located in the northeastern part of the country on the Atlantic coast. It is the fourth most populous Brazilian state after São Paulo, Minas Gerais and Rio de Janeiro, and the fifth-largest in size...

, Espírito Santo
Espírito Santo
Espírito Santo is one of the states of southeastern Brazil, often referred to by the abbreviation "ES". Its capital is Vitória and the largest city is Vila Velha. The name of the state means literally "holy spirit" after the Holy Ghost of Christianity...

, Minas Gerais
Minas Gerais
Minas Gerais is one of the 26 states of Brazil, of which it is the second most populous, the third richest, and the fourth largest in area. Minas Gerais is the Brazilian state with the largest number of Presidents of Brazil, the current one, Dilma Rousseff, being one of them. The capital is the...

, Rio de Janeiro
Rio de Janeiro (state)
Rio de Janeiro is one of the 27 states of Brazil.Rio de Janeiro has the second largest economy of Brazil behind only São Paulo state.The state of Rio de Janeiro is located within the Brazilian geopolitical region classified as the Southeast...

, and São Paulo
São Paulo (state)
São Paulo is a state in Brazil. It is the major industrial and economic powerhouse of the Brazilian economy. Named after Saint Paul, São Paulo has the largest population, industrial complex, and economic production in the country. It is the richest state in Brazil...

. Of all the Callicebus species, Atlantic titi monkeys have the largest geographic range except for C. torquatus
Collared Titi
The collared titi, Callicebus torquatus, is a species or a closely related complex of species of titi, a type of New World monkey, from South America.- Taxonomy :...

, covering approximately 1,000 kilometers. They customarily share their living area with other monkeys such as the lion tamarin
Lion tamarin
The four species of lion tamarins make up the genus Leontopithecus. They are small New World monkeys named for the mane surrounding their face. Living in the eastern rainforests of Brazil, like all other callitrichids they are arboreal. Lion tamarins weigh up to 900 grams and are about...

 and spider monkey
Spider monkey
Spider monkeys of the genus Ateles are New World monkeys in the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil...

.

Subspecies variations

Distinctions between each of the "Callicebus" subspecies are based on coat color. The evolution of these coat colors is termed metachromism. The pigments are produced by melanocyte
Melanocyte
-External links: - "Eye: fovea, RPE" - "Integument: pigmented skin"...

s which deposit the pigments into the medulla
Medulla (hair)
-Importance in forensics:Hair can easily be discredited as belonging to a human with the presence of medulla. Most other mammals possess one which is easily visible under a microscope. Humans of Middle-Eastern origin, however, do, in fact, possess a thin, less visible medulla...

 of growing hair so that the hair grows with the color of that distinct pigment. The characteristic pigment of the Callicebus is eumelanin (dark brown or black) found in hair, skin, and iris (usually on the forehead, crown and tail).

Diet

Atlantic titis are opportunistic feeders. In other words, they eat based on the abundance of food that is available to them in each season. Their food choices are not usually very selective, but they are frugivorous, usually eating fleshy fruits, seeds, and leaves.

Geophagy

It has been documented that they can be geophagic
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...

. Various hypothesis exist for their geophagic nature. These include the following:
  • Dietary mineral supplementation
  • Adjustment of pH balance in the stomach
  • Absorption of plant toxins
  • Tactile sensation in the mouth
  • Physiochemical effects on the gastrointestinal tract
  • Relief from infestation of internal parasites

Masked Titis are tree monkeys. It is not customary to find them on the forest floor. It speculated that they prefer to remain in the rainforest trees to avoid snake predation. Interestingly, they remain at least 5 meters above the ground for 99% of their daily activities. Due to their frugivorous nature, they have rarely been observed on the ground foraging for insects or small vertebrates. Instead they prefer to remain high in the tree limbs of the dense eastern Brazilian rainforest.
Because they prefer not to be on the ground, the soil researchers have observed them eating was found atop ant mounds. Picking soil atop ant mounds serves as an advantage to the Masked Titis for the following reasons:
  • It is a safer location to choose soil because it allows the monkeys to scan for surrounding predators and gives them close access to the protection of the trees
  • Aggregate soil is easier for them to grasp with their opposable fingers than forest floor topsoil (which is not as held together as soil that has been cemented together by leaf-cutting ants)
  • There is less leaf litter and forest debris on ant mounds, thus decreasing the amount of time they are exposed to predators


For many years, researchers believed that geophagy might be have been used by the Masked Titi's as a sodium supplement as their high foliage diets were quite low in sodium. However, results of geochemical analysis of the soils eaten by C. personatus demonstrated that these soils did not contain high quantities of sodium. Although the soil consumed by Masked Titis was found to contain many different minerals in comparison to random soil samples, these minerals where not necessarily a valuable component of the Titi diet. Therefore, it was concluded that soil was not a nutritionally significant portion of their diet.
Another hypothesis suggested that the soil served as an antacid. However, results of the most recent studies demonstrated that the soil consumed by the monkeys contained a very low pH compared to random soil samples. Therefore, it seems geophagy is not principally used to buffer the stomach pH levels.
In addition, because the clay molecule has a large flat structure that is ideal for toxin absorption, researchers also suggested that soil could serve to absorb the toxins acquired by the consumption of such a high quantity and variety of forest foliage. Unfortunately, more research needs to be conducted on this hypothesis to prove its validity as currently no studies have been conducted on the toxicity levels in the fruit eaten by the Masked Titis. It is also important to note that termite mound soil was preferred by the Titis to any other type of soil available to them. The reason for such a preference is not yet known.

Survival

Regardless of the presence of humans in Brazilian forests, titi monkeys customarily venture to dwell in "disturbed" forests (forests that have been cut down or invaded by humans) as long as the food availability is higher than in undisturbed forests. The Atlantic forest of eastern Brazil has been cut down to 5% of its original state with only 2% of that being undisturbed forest. Their existence is completely dependent on their ability to successfully reside in disturbed forests. However, Titi's do not seem to be aware of the difference between a disturbed and undisturbed forest. As previously mentioned, they feed opportunistically and therefore will reside in whatever forest has the most food available. As long as food is available to them (even is humans provide this food), it is feasible that the monkeys survive the deforestation of much of the Southern American rain forests.

Reproduction

Atlantic Titis are usually monogamous (they stay with one mate throughout their entire lifespan). They have one offspring per year. It is difficult to distinguish between the sexes externally, however Atlantic Titi family dynamics indicate that the father carries the infant at all times during the nursing.

Level of daily activity

Two major types of activity have been observed in Masked Titis. The first is characterized by two feeding periods separated by a relatively long resting period. The two feeding periods are in different locations in which a significant portion of the day was spent traveling to the second location to feed. The second activity pattern contained three feeding periods also separated by resting periods. However, travel was much more evenly dispersed throughout the day in this pattern. Each feeding period lasted approximately 2-3 hours, and traveling usually consumed approximately 20% of their day.

Masked Titis do have territorial displays throughout the day. The defend their territories by loud intergroup vocalizations to other groups of monkeys and to other animals in the general area. Additionaly, all Titi monkeys have "Dawn Calls" in the mornings in which the male and female usually duet the same song.
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