Long-tailed Weasel
Encyclopedia
The long-tailed weasel (Mustela frenata), also known as the bridled weasel or big stoat is a species of mustelid
distributed from southern Canada
throughout all the United States
and Mexico
, southward through all of Central America
and into northern South America
.
. The species thrived during the Ice Age
, as its small size and long body allowed it to easily operate beneath snow, as well as hunt in burrows. The long-tailed weasel and the stoat remained separated until half a million years ago, when falling sea level
s exposed the Bering land bridge
, thus allowing the stoat to cross into North America. However, unlike the latter species, the long-tailed weasel never crossed the land bridge, and did not spread into Eurasia.
Mustela in North America, with a total length of 300–350 mm and a tail comprising 40–70% of the head and body length. In most populations, females are 10–15% smaller than males, thus making them about the same size as large male stoat
s. The eyes are black in daylight, but glow bright emerald green when caught in a spotlight at night. The dorsal fur is brown in summer, while the underparts are whitish and tinged with yellowish or buffy brown from the chin to the inguinal region. The tail has a distinct black tip. Long-tailed weasels in Florida and the southwestern US may have facial markings of a white or yellowish colour. In northern areas in winter, the long-tailed weasel's fur becomes white, sometimes with yellow tints, but the tail retains its black tip. The long-tailed weasel moults twice annually, once in autumn (October to mid-November) and once in spring (March–April). Each moult takes about 3–4 weeks and is governed by day length and mediated by the pituitary gland
. Unlike the stoat, whose sole
s are thickly furred all year, the long-tailed weasel's soles are naked in summer. The long-tailed weasel has well-developed anal scent glands, which produce a strong and musky odour. Unlike skunk
s, which spray their musk, the long-tailed weasel drags and rubs its body over surfaces in order to leave the scent.
lasts 10 months, with actual embryonic development taking place only during the last four weeks of this period, an adaptation to timing births for spring, when small mammalsare abundant. Litter size generally consists of 5–8 kits, which are born in April–May. The kits are born partially naked, blind and weighing 3 grams, about the same weight of a hummingbird
. The long-tailed weasel's growth rate
is rapid, as by the age of three weeks, the kits are well furred, can crawl outside the nest and eat meat. At this time, the kits weigh 21–27 grams. At five weeks of age, the kit's eyes open, and they become physically active and vocal. Weaning
begins at this stage, with the kits emerging from the nest and accompanying the mother in hunting trips a week later. The kits are fully grown by autumn and, by this time, the family disbands. The females are able to breed at 3–4 months of age, while males become sexually mature at 15–18 months.
holes. The 22–30 cm diameter nest chamber is situated around 60 cm from the burrow entrance, and is lined with straw and the fur of prey.
, by rushing at them and kills them with one bite to the head. With large prey, such as rabbit
s, the long-tailed weasel strikes quickly, taking its prey off guard. It grabs the nearest part of the animal and climbs upon its body, maintaining its hold with its feet. The long-tailed weasel then manoevres itself to inflict a lethal bite to the neck.
The long-tailed weasel is an obligate carnivore which prefers its prey to be fresh or alive, eating only the carrion stored within its burrows. Rodent
s are almost exclusively taken when they are available. Its primary prey consists of mice, rat
s, squirrel
s, chipmunk
s, shrew
s, mole
s and rabbits. Occasionally, it may eat small bird
s, bird eggs, reptile
s, amphibian
s, fish
, earthworm
s and some insect
s. The species has also been observed to take bat
s from nursery colonies. It occasionally surplus kill
s, usually in spring when the kits are being fed, and again in autumn. Some of the surplus kills may be cache
d, but are usually left uneaten. Kits in captivity eat from ¼–½ of their body weight in 24 hours, while adults eat only one fifth to one third. After killing its prey, the long-tailed weasel laps up the blood, but does not suck it, as is popularly believed. With small prey, also the fur, feathers, flesh and bones are consumed, but only some flesh is eaten from large prey. When stealing eggs, the long-tailed weasel removes each egg from its nest one at a time, then carries it in its mouth to a safe location where it bites off the top and licks out the contents.
Mustelidae
Mustelidae , commonly referred to as the weasel family, are a family of carnivorous mammals. Mustelids are diverse and the largest family in the order Carnivora, at least partly because in the past it has been a catch-all category for many early or poorly differentiated taxa...
distributed from southern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
throughout all the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, southward through all of Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and into northern 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...
.
Evolution
The long-tailed weasel is the product of a process begun 5–7 million years ago, when northern forests were replaced by open grassland, thus prompting an explosive evolution of small, burrowing rodents. The long-tailed weasel's ancestors were larger than the current form, and underwent a reduction in size to exploit the new food source. The long-tailed weasel arose in North America 2 million years ago, shortly before the stoat evolved as its mirror image in EurasiaEurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
. The species thrived during the Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
, as its small size and long body allowed it to easily operate beneath snow, as well as hunt in burrows. The long-tailed weasel and the stoat remained separated until half a million years ago, when falling sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
s exposed the Bering land bridge
Bering land bridge
The Bering land bridge was a land bridge roughly 1,000 miles wide at its greatest extent, which joined present-day Alaska and eastern Siberia at various times during the Pleistocene ice ages. Like most of Siberia and all of Manchuria, Beringia was not glaciated because snowfall was extremely light...
, thus allowing the stoat to cross into North America. However, unlike the latter species, the long-tailed weasel never crossed the land bridge, and did not spread into Eurasia.
Physical description
The long-tailed weasel is one of the largest members of the genusGenus
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...
Mustela in North America, with a total length of 300–350 mm and a tail comprising 40–70% of the head and body length. In most populations, females are 10–15% smaller than males, thus making them about the same size as large male stoat
Stoat
The stoat , also known as the ermine or short-tailed weasel, is a species of Mustelid native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip...
s. The eyes are black in daylight, but glow bright emerald green when caught in a spotlight at night. The dorsal fur is brown in summer, while the underparts are whitish and tinged with yellowish or buffy brown from the chin to the inguinal region. The tail has a distinct black tip. Long-tailed weasels in Florida and the southwestern US may have facial markings of a white or yellowish colour. In northern areas in winter, the long-tailed weasel's fur becomes white, sometimes with yellow tints, but the tail retains its black tip. The long-tailed weasel moults twice annually, once in autumn (October to mid-November) and once in spring (March–April). Each moult takes about 3–4 weeks and is governed by day length and mediated by the pituitary gland
Pituitary gland
In vertebrate anatomy the pituitary gland, or hypophysis, is an endocrine gland about the size of a pea and weighing 0.5 g , in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity covered by a dural fold...
. Unlike the stoat, whose sole
Sole (foot)
The sole is the bottom of the foot.In humans the sole of the foot is anatomically referred to as the plantar aspect. The equivalent surface in ungulates is the hoof.- Human sole :...
s are thickly furred all year, the long-tailed weasel's soles are naked in summer. The long-tailed weasel has well-developed anal scent glands, which produce a strong and musky odour. Unlike skunk
Skunk
Skunks are mammals best known for their ability to secrete a liquid with a strong, foul odor. General appearance varies from species to species, from black-and-white to brown or cream colored. Skunks belong to the family Mephitidae and to the order Carnivora...
s, which spray their musk, the long-tailed weasel drags and rubs its body over surfaces in order to leave the scent.
Reproduction and development
The long-tailed weasel mates in July–August, with implantation of the fertilized egg on the uterine wall being delayed until about March. The gestation periodGestation period
For mammals the gestation period is the time in which a fetus develops, beginning with fertilization and ending at birth. The duration of this period varies between species.-Duration:...
lasts 10 months, with actual embryonic development taking place only during the last four weeks of this period, an adaptation to timing births for spring, when small mammalsare abundant. Litter size generally consists of 5–8 kits, which are born in April–May. The kits are born partially naked, blind and weighing 3 grams, about the same weight of a hummingbird
Hummingbird
Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...
. The long-tailed weasel's growth rate
Ageing
Ageing or aging is the accumulation of changes in a person over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline...
is rapid, as by the age of three weeks, the kits are well furred, can crawl outside the nest and eat meat. At this time, the kits weigh 21–27 grams. At five weeks of age, the kit's eyes open, and they become physically active and vocal. Weaning
Weaning
Weaning is the process of gradually introducing a mammal infant, either human or animal, to what will be its adult diet and withdrawing the supply of its mother's milk.The process takes place only in mammals, as only mammals produce milk...
begins at this stage, with the kits emerging from the nest and accompanying the mother in hunting trips a week later. The kits are fully grown by autumn and, by this time, the family disbands. The females are able to breed at 3–4 months of age, while males become sexually mature at 15–18 months.
Denning and sheltering behaviour
The long-tailed weasel dens in ground burrows, under stumps or beneath rock piles. It usually does not dig its own burrows, but commonly uses abandoned chipmunkChipmunk
Chipmunks are small striped squirrels native to North America and Asia. They are usually classed either as a single genus with three subgenera, or as three genera.-Etymology and taxonomy:...
holes. The 22–30 cm diameter nest chamber is situated around 60 cm from the burrow entrance, and is lined with straw and the fur of prey.
Diet
The long-tailed weasel is a fearless and aggressive hunter which may attack animals far larger than itself. When stalking, it waves its head from side to side in order to pick up the scent of its prey. It hunts small prey, such as miceMouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
, by rushing at them and kills them with one bite to the head. With large prey, such as rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s, the long-tailed weasel strikes quickly, taking its prey off guard. It grabs the nearest part of the animal and climbs upon its body, maintaining its hold with its feet. The long-tailed weasel then manoevres itself to inflict a lethal bite to the neck.
The long-tailed weasel is an obligate carnivore which prefers its prey to be fresh or alive, eating only the carrion stored within its burrows. Rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s are almost exclusively taken when they are available. Its primary prey consists of mice, rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, squirrel
Squirrel
Squirrels belong to a large family of small or medium-sized rodents called the Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots , flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and Africa and have been introduced to Australia...
s, chipmunk
Chipmunk
Chipmunks are small striped squirrels native to North America and Asia. They are usually classed either as a single genus with three subgenera, or as three genera.-Etymology and taxonomy:...
s, shrew
Shrew
A shrew or shrew mouse is a small molelike mammal classified in the order Soricomorpha. True shrews are also not to be confused with West Indies shrews, treeshrews, otter shrews, or elephant shrews, which belong to different families or orders.Although its external appearance is generally that of...
s, mole
Mole (animal)
Moles are small cylindrical mammals adapted to a subterranean lifestyle. They have velvety fur; tiny or invisible ears and eyes; and short, powerful limbs with large paws oriented for digging. The term is especially and most properly used for the true moles, those of the Talpidae family in the...
s and rabbits. Occasionally, it may eat small bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s, bird eggs, reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
s and some insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s. The species has also been observed to take bat
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s from nursery colonies. It occasionally surplus kill
Surplus killing
Surplus killing is the behavior predators exhibit when they kill more prey than they can immediately use. They may partially consume, cache, or abandon intact prey...
s, usually in spring when the kits are being fed, and again in autumn. Some of the surplus kills may be cache
Cache
In computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere...
d, but are usually left uneaten. Kits in captivity eat from ¼–½ of their body weight in 24 hours, while adults eat only one fifth to one third. After killing its prey, the long-tailed weasel laps up the blood, but does not suck it, as is popularly believed. With small prey, also the fur, feathers, flesh and bones are consumed, but only some flesh is eaten from large prey. When stealing eggs, the long-tailed weasel removes each egg from its nest one at a time, then carries it in its mouth to a safe location where it bites off the top and licks out the contents.
Subspecies
, 42 subspecies are recognised.| Subspecies | Trinomial authority | Description | Range | Synonyms |
|---|---|---|---|---|
| Bridled weaselMustela f. frenata (Nominate subspecies) |
Lichtenstein, 1831 | A large subspecies with a long tail, relatively short black tip and has a black head with conspicuous white markings | Mexico | aequatorialis (Coues, 1877) brasiliensis (Sevastianoff, 1813) mexicanus (Coues, 1877) |
| Mustela f. affinis | Gray, 1874 | A large, very dark subspecies with very little white marking on the face | costaricensis (J. A. Allen, 1916) macrurus (J. A. Allen, 1912) meridana (Hollister, 1914) |
|
| Mustela f. agilis | Tschudi, 1844 | macrura (J. A. Allen 1916) | ||
| Black Hills weaselMustela f. alleni | Merriam, 1896 | Similair to arizonensis in size and general characters, but with yellower upper parts | Black Hills Black Hills The Black Hills are a small, isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, USA. Set off from the main body of the Rocky Mountains, the region is something of a geological anomaly—accurately described as an "island of... , South Dakota South Dakota South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over... |
|
| Mustela f. altifrontalis | Hall, 1936 | saturata (Miller, 1912) | ||
| Arizona weaselMustela f. arizonensis | Mearns, 1891 | Similair to longicauda, but smaller in size | Sierra Nevada and Rocky Mountain systems, reaching British Columbia in the Rocky Mountain region | |
| Mustela f. arthuri | Hall, 1927 | |||
| Mustela e. celenda | Hall, 1944 | |||
| Mustela f. aureoventris | Gray, 1864 | affinis (Lönnberg, 1913) jelskii (Taczanowski, 1881) macrura (Taczanowski, 1874) |
||
| Mustela f. boliviensis | Hall, 1938 | |||
| Mustela f. costaricensis | Goldman, 1912 | brasiliensis (Gray, 1874) | ||
| Mustela f. effera | Hall, 1936 | |||
| Chiapas weaselMustela f. goldmani | Merriam, 1896 | Similair to frenata in size and general characters, but with a longer tail and hind feet, darker fur and more restricted white markings | Mountains of southeastern Chiapas | |
| Mustela f. gracilis | Brown, 1908 | |||
| Mustela f. helleri | Hall, 1935 | |||
| Mustela f. inyoensis | Hall, 1936 | |||
| Mustela f. latirostra | Hall, 1896 | arizonensis (Grinnell and Swarth, 1913) | ||
| Mustela f. leucoparia | Merriam, 1896 | Similair to frenata, but slightly larger and with more extensive white markings | ||
| Common long-tailed weaselMustela f. longicauda |
Bonaparte, 1838 | A large subspecies with a very long tail and short black tip. The upper parts are pale yellowish brown or pale raw amber brown, while the underparts vary in colour from strong buffy yellow to ochraceous orange | Great Plains Great Plains The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S... from Kansas Kansas Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south... northward |
|
| Mustela f. macrophonius | Elliot, 1905 | |||
| Mustela f. munda | Bangs, 1899 | |||
| Mustela f. neomexicanus | Barber and Cockerell, 1898 | |||
| Mustela f. nevadensis | Hall, 1936 | longicauda (Coues, 1891) | ||
| Mustela f. nicaraguae | J. A. Allen, 1916 | |||
| Mustela f. nigriauris | Hall, 1936 | xanthogenys (Gray, 1874) | ||
Mustela f. notius |
Bangs, 1899 | |||
| New York weaselMustela f. noveboracensis |
Emmons, 1840 | A large subspecies, with a shorter tail than longicauda. The upper parts are rich, dark chocolate brown, while the underparts and upper lip are white and washed with yellowish. | Eastern United States from southern Maine to North Carolina and west to Illinois | fusca (DeKay, 1842) richardsonii (Baird, 1858) |
| Mustela f. occisor | Bangs, 1899 | |||
| Mustela f. olivacea | Howell, 1913 | |||
| Oregon weaselMustela f. oregonensis | Merriam, 1896 | Similair to xanthogenys, but larger, darker in colour and has more restricted facial markings | Rogue River Valley, Oregon | |
| Mustela f. oribasus | Bangs, 1899 | |||
| Mustela f. panamensis | Hall, 1932 | |||
| Florida weaselMustela f. peninsulae |
Rhoads, 1894 | Equal in size to noveboracensis, but with a skull more similair to that of longicauda. The upper parts are dull chocolate brown, while the underparts are yellowish | Florida Peninsula | |
| Mustela f. perda | Merriam, 1902 | |||
| Mustela f. perotae | Hall, 1936 | |||
| Mustela f. primulina | Jackson, 1913 | |||
| Mustela f. pulchra | Hall, 1936 | |||
| Cascade Mountain weaselMustela f. saturata | Merriam, 1896 | Similair to arizonensis, but larger and darker, with an ochraceous belly and distinct spots behind the corners of the mouth | ||
| Mustela f. spadix | Bangs, 1896 | Similair to longicauda, but much darker | ||
| Mustela f. texensis | Hall, 1936 | |||
| Tropical weaselMustela f. tropicalis |
Merriam, 1896 | Similair to frenata, but much smaller and darker, with less extensive white facial marking and an orange underbelly | Tropical coast belt of southern Mexico and Guatemala from Vera Cruz southward | frenatus (Coues, 1877) noveboracensis (DeKay, 1840) perdus (Merriam, 1902) richardsoni (Bonaparte, 1838) |
| Washington weaselMustela f. washingtoni | Merriam, 1896 | Similair to noveboracensis in size, but with a longer tail and shorter black tip | Washington state | |
| California weaselMustela f. xanthogenys | Gray, 1843 | A medium sized subspecies with a long tail, a face marked with whitish and ochraceous underparts | Sonoran and Transition faunas of California, on both sides of Sierra Nevada | |