The long-tailed weasel (''Neogale frenata''), also known as the bridled weasel, masked ermine, or big stoat, is a species of
mustelid
The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in ...
distributed from southern
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
throughout all the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
and
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, southward through all of
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
and into northern
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
. It is distinct from the
short-tailed weasel (''Mustela erminea''), also known as a "stoat", a close relation in the genus ''
Mustela'' that originated in Eurasia and crossed into North America some half million years ago; the two species are visually similar, especially the black tail tip.
Taxonomy
Originally described in the genus ''
Mustela'', a 2021 study reclassified it into the genus ''
Neogale
''Neogale'' is a genus of mustelid native to the Americas, ranging from Alaska south to Bolivia. Members of this genus are known as New World weasels.
Taxonomy
Members in this genus were formerly classified into the genera '' Mustela'' and '' ...
'' along with 2 other former ''Mustela'' species, as well as the two species formerly classified in ''
Neovison
''Neogale'' is a genus of mustelid native to the Americas, ranging from Alaska south to Bolivia. Members of this genus are known as New World weasels.
Taxonomy
Members in this genus were formerly classified into the genera '' Mustela'' and ' ...
''.
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
The stoat (''Mustela erminea''), also known as the Eurasian ermine, Beringian ermine and ermine, is a mustelid native to Eurasia and the northern portions of North America. Because of its wide circumpolar distribution, it is listed as Least Conc ...
evolved as its mirror image in
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
. The species thrived during the
Ice Age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...
, 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
Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...
s exposed the
Bering land bridge
Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 72 degrees north latitude in the Chukchi Sea; and on the south by the tip of ...
, 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.
Description
The long-tailed weasel is one of the larger
weasel
Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets and European mink. Members of this genus are small, active predators, with long and slender bo ...
s (comprising both ''Neogale'' and ''Mustela'') in North America. There is substantial disagreement both on the upper end of their size and difference in size by sex by source: one indicates a body length of and a tail comprising 40–70% of the head and body length. It adds that in most populations, females are 10–15% smaller than males,
thus making them about the same size as large male
stoat
The stoat (''Mustela erminea''), also known as the Eurasian ermine, Beringian ermine and ermine, is a mustelid native to Eurasia and the northern portions of North America. Because of its wide circumpolar distribution, it is listed as Least Conc ...
s, according to a second source.
A third states they range from 11 to 22 inches (280–560 mm) in length, with the tail measuring an additional 3 to 6 inches (80–150 mm). It maintains the long-tailed weasel weighs between 3 and 9 ounces (85-267 g) with males being about twice as large as the females.
[LONG-TAILED WEASEL (Mustela frenata), Description; Northern State University, Aberdeen, South Dakota](_blank)
/ref>
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
In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...
. Unlike the stoat, whose soles 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
Skunks are mammals in the family Mephitidae. They are known for their ability to spray a liquid with a strong, unpleasant scent from their anal glands. Different species of skunk vary in appearance from black-and-white to brown, cream or ginge ...
s, which spray their musk, the long-tailed weasel drags and rubs its body over surfaces in order to leave the scent, to mark their territory and, when startled or threatened, to discourage predators.
Identification
Tracks and scat
The footprint of a long-tailed weasel is about 1 inch (25 mm) long. Although they have five toes, only four of them can be seen in their tracks. The only exception to this is when walking in the snow or mud, all five of their toes are shown. Their footprints will also appear heavier if the weasel is carrying food. Another way to determine the presence of a weasel is by looking for wavy indents made by their tails in the snow.
The long-tailed weasel uses one spot to leave their feces. This spot is usually near where they burrow. They'll continuously use this spot for their droppings until it gets covered by environmental changes.
Distinguishing features
A black-tipped tail, yellowish-white belly fur, and brown fur on its back and sides are distinguishing for the long-tailed weasel. Additionally, the long-tailed weasel has long whiskers
Vibrissae (; singular: vibrissa; ), more generally called Whiskers, are a type of stiff, functional hair used by mammals to touch, sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are c ...
, a long narrow body, and a long tail that is approximately half the length of the body and head of the weasel.["Long-tailed Weasel Facts"](_blank)
''Washington Nature Mapping Program''. Retrieved 3 June 2021.[NatureWorks]
''NHPBS
New Hampshire PBS (NHPBS), known as New Hampshire Public Television (NHPTV) prior to October 1, 2017, is a Public Broadcasting Service (PBS) member network serving the U.S. state of New Hampshire. It is operated by New Hampshire Public Broadcast ...
''. Retrieved 3 June 2021.[Montana Field Guide]
"Long-tailed Weasel — Mustela frenata"
''Montana Natural Heritage Program and Montana Fish, Wildlife and Parks''. Retrieved 3 June 2021. Compared to the short-tailed weasel the long-tailed weasel lacks a white line on the insides of its legs.
Behaviour
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 period
In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus, and ends once it ...
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 mammals are 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
Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics aro ...
. 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 the young become physically active and vocal. Weaning
Weaning is the process of gradually introducing an infant human or another mammal to what will be its adult diet while withdrawing the supply of its mother's milk.
The process takes place only in mammals, as only mammals produce milk. The infan ...
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, at which 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 chipmunk
Chipmunks are small, striped rodents of the family Sciuridae. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia.
Taxonomy and systematics
Chipmunks may be classified either as ...
holes. The diameter nest chamber is situated around from the burrow entrance, and is lined with straw and the fur of prey.
Defense
The enemies of the long-tailed weasel are usually coyotes
The coyote (''Canis latrans'') is a species of canis, canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecologica ...
, foxes
Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush'').
Twelve sp ...
, wildcats
The wildcat is a species complex comprising two small wild cat species: the European wildcat (''Felis silvestris'') and the African wildcat (''F. lybica''). The European wildcat inhabits forests in Europe, Anatolia and the Caucasus, while the ...
, wolves
The wolf (''Canis lupus''; plural, : wolves), also known as the gray wolf or grey wolf, is a large Canis, canine native to Eurasia and North America. More than thirty subspecies of Canis lupus, subspecies of ''Canis lupus'' have been reco ...
, and the Canadian lynx
The Canada lynx (''Lynx canadensis''), or Canadian lynx, is a medium-sized North American lynx that ranges across Alaska, Canada, and northern areas of the contiguous United States. It is characterized by its long, dense fur, triangular ears w ...
. The weasel will give off its musky odor, however, this is not primarily used when encountering other creatures. When leaving an area they were just in, they will leave their odor behind. This is done by the weasels taking themselves and hauling their bodies across surfaces they just interacted with. The long-tailed weasel does this to "discourage predators" from coming back to the area, possibly indicating that the weasel considers this a safe haven for return. This type of reaction is also reserved for when the weasel feels it is in danger, or when it is looking for a mate. Tree-climbing is another type of defense mechanism that long-tailed weasels utilize against predators on the ground. These weasels will climb up a reasonable height of a tree when they sense that they are in danger. They will then sit silent and "motionless", while looking at their presumed predator. These weasels keep their guard up like this until the predator leaves, and when the weasel considers itself no longer in danger.
Another common defense of long-tailed weasels is its black-tipped tail, which differs in color from the rest of the body. When the long-tailed weasel becomes more white in the winter, this defense mechanism is especially used. The black-tipped tail distracts predators from the rest of the body, as it is more visible to the eye of a predator. This causes the visibility of the actual weasel to be rather difficult and makes the predator attack the tail instead of the weasel. The weasel is allowed to escape the predator because of this.
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 mice
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
, by rushing at them and killing them with one bite to the head. With large prey, such as rabbit
Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit speci ...
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 manoeuvres itself to inflict a lethal bite to the neck.
The long-tailed weasel is an obligate carnivore
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...
which prefers its prey to be fresh or alive, eating only the carrion stored within its burrows. Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
s are almost exclusively taken when they are available. Its primary prey consists of mice
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
, rat
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...
s, squirrel
Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...
s, chipmunk
Chipmunks are small, striped rodents of the family Sciuridae. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia.
Taxonomy and systematics
Chipmunks may be classified either as ...
s, shrew
Shrews (family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to different fa ...
s, mole
Mole (or Molé) may refer to:
Animals
* Mole (animal) or "true mole", mammals in the family Talpidae, found in Eurasia and North America
* Golden moles, southern African mammals in the family Chrysochloridae, similar to but unrelated to Talpida ...
s and rabbits. Occasionally, it may eat small bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
s, bird eggs, reptile
Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...
s, amphibian
Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...
s, fish
Fish are aquatic, craniate, gill-bearing 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. Approximately 95% of li ...
, earthworm
An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. Th ...
s and some insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s. The species has also been observed to take bat
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...
s from nursery colonies. It occasionally surplus kills, usually in spring when the kits are being fed, and again in autumn. Some of the surplus kills may be cached, 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 or if they have babies in the den they may hold it in their mouth all the way back to them.
Subspecies
, 42 subspecies are recognised.
Cultural meanings
In North America, Native Americans (in the region of