Weasels

The taxonomy of weasels can be very confusing, as evolution has lead to a variety of species sharing a similar anatomy. Since “mustela” is Latin for weasel, the family Mustelidae is often simply referred to as the “weasel family”. However, given our better understanding of genetics today, this term can be misleading in the English language. For example, many distinctive mustelids (such as badgers, otters, martens, and the wolverine) are related to weasels, or in some respects “weasel-like”, but are generally not considered “true” weasels. In most cases it is believed only members of the genus Mustela are true weasels.(1) All in all the word “weasel” has developed such a broad, sometimes arbitrary definition that it is not consistently applied or understood.

The weasels are the tiniest members of the family Mustelidae. They have long, slender bodies adapted to pursuing prey into their burrows, losing little speed when their normal gait transitions to a crouching position. Despite being the smallest mustelids, some attack and kill prey up to ten times their size; a risky but rewarding ability when the need for protein is so great. Weasels vary in body length from approximately 13 to 52 cm (5 to 20 in), with females being smaller than the males. Their tails may be from 1.2 to 29.4 cm (0.5 to 11.5 in) long.

They usually have red or brown upper coats and white bellies. Depending on the subspecies, only three species of weasel are known for changing to their white winter coats—the least weasel (M. nivalis), long-tailed weasel (M. frenata), and stoat (M. erminea).(2)

How “weasel” can be a misleading common name

Usually in England and New Zealand, “weasel” is a generic common name used to refer to the least weasel, while in North America the term often applies to any of the three small native Mustela species.(3) This has led many people to assume that there is only one or three species of weasel in existence, or that these species are somehow more “weasel-like” compared to others. The truth is there are numerous different species and subspecies of weasel; many of which have their own unique features, size, and range, including abilities and vulnerabilities relative to their respective climate.

A family misunderstood

Centuries of human-centric myths, superstations, and rumors have contributed to weasels being some of the most stigmatised animals on Earth. The common expression “weasel out of”, and the misnomer term “weasel word” also have not helped their image. To this day, society continues to habitually attribute human traits or intentions to these animals—believing they are simply bloodthirsty, egg-sucking creatures that kill for pleasure.

Like most wild predators, weasels hunt and do what they must to survive. Small predators in particular live on the edge with threats around every corner, including their own high metabolic rate and short digestive tract. It is a constant race around the clock to stay warm and alive(4), so they have to be more intense than most to make it through the day, and unless we know the reasons for why they evolved to behave as they do, it is easy to misinterpret their intentions. We are not saying they do not enjoy chasing their prey or the taste of their food, but it is not pure malice for fun.

Surplus killing

Some would say another reason weasels are thought to kill for pleasure is due to the act of surplus killing—especially in regard to domestic fowl. Though the exact reason is inconclusive, it is possible that, when presented with an abundance of food, multiple prey is killed so the weasel may return to cache the remainder for later consumption.(5) It is this similar evolutionary programming that has enabled other carnivorous animals to survive.(6)

A tunnel hunter has to stay as slim as possible, which is not without costs—the high metabolic rate and limited storage of body fat will cause them to perish if they do not eat within a few hours throughout the day.(7) Weasels sometimes kill more than they can eat, but it is also possible the weasel is unable to return to eat or cache the remainder of its kill due to someone scaring it off, or removing the carcass in its absence.

They do not live in packs

There is a misconception that weasels live in packs, based on observations of females with well-grown young. Male kits will quickly outgrow their mother. The sexual dimorphism is the most pronounced in the smaller weasel species.

They do not suck eggs

Despite the claim in a couple of William Shakespeare’s plays,(8) weasels do not suck eggs. In relation, the misnomer term “weasel word” may have first appeared in Stewart Chaplin’s 1900 short story “Stained Glass Political Platform”, in which weasel words were described as “words that suck the life out of the words next to them, just as a weasel sucks the egg and leaves the shell”.(9)

The truth is weasels (more specifically stoats) have evolved a particular way to consume eggs. They bite a small hole in the egg, turn it so it lays in a horizontal position, and lick the liquid content when it starts flowing.(10)(11) So essentially they drain eggs, not suck them. Seeing empty eggshells left behind may have given rise to the myth that weasels suck eggs, which—due to lacking the necessary jaw muscles—they are not physically capable of doing.(12)

They do not suck or drink blood

There have been baseless claims that weasels (and other weasel-like mustelids) will suck the blood of their prey. As with eggs, weasels do not—and physically cannot—suck blood.(13)(14) Some argue that weasels are capable of sucking blood because they draw milk from their mother when unweaned, however, this is called “suckling”, which is a completely different reflex from “sucking”. Weasels may lap up a small amount of blood if it trickles from a wound, or to get moisture and extra nutrients with their food in a practical sense, but there is no significant proof that they actually indulge in it.

Following an act of surplus killing, seeing uneaten animals with wounds to their necks may have given rise to the myth that their blood was simply “sucked out” by the weasel. In addition, weasels are not hematophagous animals and do not “drink” blood. People only thought they were seeing weasels drinking the blood of their prey, and this was enough to give rise to this myth as well.

References

  1. Koepfli, Klaus-Peter, et al. “Multigene phylogeny of the Mustelidae: resolving relationships, tempo and biogeographic history of a mammalian adaptive radiation.” BMC biology 6.1 (2008): 10.
  2. Rich Landers “A peek at animals that turn white in winter” The Spokesman-Review (Jan. 10, 2012). Accessed 11 of June, 2020.
  3. King, Carolyn M., and Roger A. Powell. The natural history of weasels and stoats: ecology, behavior, and management. Oxford University Press, 2006. p. 12.
  4. Brown, James H., and Robert C. Lasiewski. “Metabolism of weasels: the cost of being long and thin.” Ecology 53.5 (1972): 939-943.
  5. Mills, L. Scott. Conservation of wildlife populations: demography, genetics, and management (2nd ed.). Hoboken, NJ: Wiley-Blackwell. p. 148
  6. Kruuk, Hans. “Surplus killing by carnivores.” Journal of Zoology 166.2 (1972): 233-244.
  7. King, Carolyn M. “The advantages and disadvantages of small size to weasels, Mustela species.” Carnivore behavior, ecology, and evolution. Springer, Boston, MA, 1989. 302-334.
  8. E. Cobham Brewer, Brewer’s Dictionary of Phrase and Fable
  9. Chaplin, Stewart. “The Stained-Glass Political Platform.” The Century Magazine (1900): 304-308.
  10. Steve Harris How to identify bird egg thieves. BBC Wildlife magazine. 30 April 2020
  11. Mark Mancini How Did Weasels Get Such a Bad Rap? 4 June 2019. HowStuffWorks.com. 30 April 2020
  12. Gerry Rising “Weasels” March 15, 1999
  13. Heidt, Gary A. “Anatomical and behavioral aspects of killing and feeding by the least weasel, Mustela nivalis L.” Journal of the Arkansas Academy of Science 26.1 (1972): 53-54.
  14. King, Carolyn M., and Roger A. Powell. The natural history of weasels and stoats: ecology, behavior, and management. Oxford University Press, 2006. p. 127.

#1 Altai Weasel (Mustela altaica)

Altai weasel in winter coat by Karunakar Rayker
Alternate summer coat: Link

The altai weasel, also known as the mountain weasel, pale weasel or solongoi, primarily lives in high-altitude regions of Asia. DNA analyses reveal they are the closest relative of the stoat, but it is unknown if they can interbreed.

Appearance

These weasels give off a delicate impression- they are sandy-brown on top and light yellow below with white paws. The face appears very defined with a dark nose and prominent zygomatic arches (cheek bones), framed with contrasting white whisker pads and chin. In summer, their coat tends to be a notably lighter shade of their winter coat.

Habitat

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Behaviour

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Reproduction

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Diet

The mountain weasels are one of the primary predators of pikas, but it will also hunt small rodents in standard weasel-fashion like voles. Other prey include muskrats, ground squirrels, rabbits, small birds, reptiles, amphibians, and the occasional insect. They are one of few mustelids that are regarded as beneficial to farmers, for their natural control of crop damaging pests.

Predators

Geographic range

Body length: 22–29 cm / 9–11.5 in (males), 22–25 cm / 9–10 in (females)
Tail length: 11–15 cm / 4–6 in (males), 9–12 cm /  3.5–5 in (females)
Weight: 217–350 g / 8–12 oz (males), 122–220 g / 4–8 oz (females)
Lifespan: Unknown (wild), unknown (captivity)
Range: Mountains of Asia, Russian central Asia, and Korea to northern India.
Conservation status: Near threatened
Subfamily: Mustelinae
Recognised subspecies(1)

  1. M. a. altaica
  2. M. a. birulai
  3. M. a. raddei
  4. M. a. temon
References
  1. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela altaica in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#2 Amazon Weasel (Mustela africana)

Illustration by Hanna W.

The Amazon weasel, also known as the tropical weasel, is a species only found in South America. Early scientific records inaccurately described their native range as Africa, which led to their misleading scientific name.(1)(2)

Appearance

Most websites that show an Amazon weasel do not have the correct photo. In fact, we were unable to find a single website that has a photo of a live Amazon weasel. For this reason we have created an illustration instead.

Their fur varies from reddish to dark brown on the dorsal surface, and is pale orange-tan on the underparts. A stripe of the same colour as that on the dorsal surface runs down the centre of the chest and throat.(1)(2) The whiskers are shorter than in any other species of weasel and the soles underneath its paws are almost bare, suggesting specific adaptations that have yet to be confirmed.

Habitat

Although the full extent of their range is unknown, the Amazon weasel is found in humid areas, mainly in forests near the banks of rivers in the Amazon basin.(2)

Behaviour

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Reproduction

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Diet

Little is known about the diet of the Amazon weasels, but they likely consume rodents and other small mammals.(2)

Predators

Geographic range

Body length: 43–52 cm / 17–20 in
Tail length: 16–21 cm / 6.3–8.3 in
Weight: 700 g / 24.7 oz
Lifespan: Unknown (wild), unknown (captivity)
Range: Brazil, Ecuador, Peru and northern Bolivia.
Conservation status: Least concern
Subfamily: Mustelinae
Recognised subspecies(3)

  1. M. a. africana
  2. M. a. stolzmanni
References
  1. Ramírez-Chaves, Héctor E., Heidi Liliana Arango-Guerra, and Bruce D. Patterson. Mustela africana (Carnivora: Mustelidae). Mammalian Species 46.917 (2014): 110-115. Page 1, figure 1.
  2. Mattice, A. 2013. Mustela africana (On-line), Animal Diversity Web. Accessed February 07, 2021.
  3. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela africana in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#3 Back-Striped Weasel (Mustela strigidorsa)

Photo used under license from 123RF.com

The back-striped weasel, also called the stripe-backed weasel, is a species that inhabits southeastern Asia.

Appearance

The back-striped weasel has a very distinguishing narrow, silvery dorsal streak extending from the top of their head down to the root of the tail. The dorsal surface is dark to reddish brown in colour, while a yellowish streak runs from the chest along the abdomen. The dorsal surface can vary in shades of brown, sometimes lighter on the head, or darker parallel to the dorsal streak. The chin and throat is pale to whitish in colour, and opens up and narrows as it moves down to the hind legs.(1)

Habitat

The back-striped weasel is thought to live primarily in the evergreen forests in the hills and mountains, but they have also been recorded in dense scrubs, secondary forests, grasslands, and farmland.(2)

Behaviour

Like many weasels, the back-striped weasels are presumed to be diurnal and mostly solitary.

Reproduction

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Diet

With limited research on the back-striped weasels, little is known about their diet, but they likely consume rodents and other small mammals like most other weasels.

Predators

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Conservation

The back-striped weasel is protected in Thailand and listed as Endangered on the China Red List.(3)(4)

Geographic range

Body length: 30–36 cm / 12–14 in
Tail length: 18–20 cm / 7.1–7.9 in
Weight: 700 g / 24.7 oz
Lifespan: Unknown (wild), unknown (captivity)
Range: Southeastern Asia
Conservation status: Least concern
Subfamily: Mustelinae
References

  1. Pocock, R. I. (1941). “Mustela strigidorsa Gray. The Back-striped Weasel”The Fauna of British India, including Ceylon and Burma. Mammalia Vol. II. Carnivora (suborders Aeluroidae (part) and Arctoidae). London: Taylor and Francis, Ltd. pp. 376–380.
  2. Abramov, A. V., et al. The stripe‐backed weasel Mustela strigidorsa: taxonomy, ecology, distribution and status. Mammal Review 38.4 (2008): 247-266.
  3. Roberton, S., et al. “Mustela strigidorsa. The IUCN Red List of Threatened Species 2016: e. T14027A45201218.” (2016).
  4. Wang, S. and Xie, Y. 2004. China Species Red List. Vol. 1 Red List. Higher Education Press, Beijing, China.

#4 Colombian Weasel (Mustela felipei)

Photo by Juan Manuel de Roux

The Colombian weasel, also known as the Don Felipe’s weasel, is a very rare weasel native to northern Ecuador and far eastern Colombia. Both their scientific and alternative common name honours the mammalogist Philip “Don Felipe” Hershkovitz.(1)

Appearance

The dorsal surface and tail are blackish-brown, while the underparts are orange-buff. There is also a distinguish ventral spot on the neck that is the same colour as the dorsum. Colombian weasels are observed to have webbed paws, which suggests they are perhaps semi-aquatic.(2)

Habitat

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Behaviour

Like other weasels, they are likely to be mainly solitary and sedentary.

Reproduction

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Diet

Little is known about the diet of the Colombian weasel, but due to their webbed paws and occurrence in riparian habitats, they are assumed to eat fish and other aquatic organisms, in addition to terrestrial small mammals, birds and insects.(2)

Predators

Geographic range

Body length: 22 cm / 8.7 in
Tail length: 11.5 cm / 4.5 in
Weight: 120–150 g / 4.23–5.29 oz
Lifespan: Unknown (wild), unknown (captivity)
Range: Western Colombia to northern Ecuador.
Conservation status: Vulnerable
Subfamily: Mustelinae
References

  1. Izor, Robert J., and Luis de la Torre. A new species of weasel (Mustela) from the highlands of Colombia, with comments on the evolution and distribution of South American weasels. Journal of Mammalogy 59.1 (1978): 92-102.
  2. Wesner, K. 2014. Mustela felipei (On-line), Animal Diversity Web. Accessed February 07, 2021.

#5 Egyptian Weasel (Mustela subpalmata)

Photo by Dick Hoek
Alternate photo: Link 1, Link 2

The Egyptian weasel is a species of weasel endemic to northeast Egypt.

Appearance

It is easy to understand why the Egyptian weasel was considered a subspecies of the least weasel, given their appearance. Like the least weasel, they are reddish to sandy brown dorsal colour contrasting with cream to white below. However, they are more bulky, with a broader muzzle, longer limbs and a much longer tail with a slightly darker tip.

Habitat

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Behaviour

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Reproduction

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Diet

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Predators

Geographic range

Body length: 36.1–43 cm / 14–17 in (males), 32.6–39 cm / 13–15 in (females)
Tail length: 11–13 cm / 4–5 in (males), 9.4–11 cm / 3.7–4.3 in (females)
Weight: 60-130 g / 2–4.5 oz (males), 45–60 g / 1.5–2 oz (females)
Lifespan: Unknown (wild), unknown (captivity)
Range: Northeastern part of Egypt near the borders of Israel and the Gaza Strip.
Conservation status: Least concern
Subfamily: Mustelinae
References

#6 Indonesian Mountain Weasel (Mustela lutreolina)

Photo by Ahmad Mursyid

The Indonesian mountain weasel is a species that lives on the islands of Java and Sumatra in Indonesia at elevations over 1,000 metres (3,280 ft).

– Source from Wikipedia. The information above needs to be edited with our own words.

Appearance

Being relatively large and bulky with an overall brown exterior and a thick tail, this weasel can easily be mistaken for an American mink or European mink, and the few photos that exist only makes it harder to identify the species among the others. They are however, lighter in build than either of those species, and have larger eyes and ears in proportion to the skull.

They are dark, rich brown in colour, with contrasting light yellow upper lip patches and chin that extends down the throat and forms a patch that is mostly angular, but can vary in shape and size between individuals. The fur is silky with a high sheen, giving a soft and elegant look.

Habitat

They live in mountainous, tropical, and rain forest areas.

Behaviour

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Reproduction

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Diet

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Predators

Geographic range

Body length: 29.7–32.1 cm / 11.5–12.5 in
Tail length: 13.6–17 cm / 5–8 in
Weight: 295–340 g / 10–12 oz
Lifespan: Unknown (wild), unknown (captivity)
Range: The islands of Java and Sumatra in Indonesia.
Conservation status: Least concern
Subfamily: Mustelinae
References

#8 Least Weasel (Mustela nivalis)

Least weasel in summer coat by Ksenia Nagaeva
Least weasel in winter coat by Vladimir Arkhipov

The least weasel, also known as the common weasel, is a species that holds many records, such as being the tiniest and the most specialized of all the weasels.

This species is the smallest weasel and member of Carnivora in the world, capable of passing through a wedding ring. While true, the species is also the most geographically widespread of the weasels, with a vast number of subspecies that have adapted to various conditions. This means the least weasel is not always the smallest by default, and some subspecies in warmer climates are often confused with rare species due to having an appearance or larger size that is very different from the image we have of them from media and documentaries.

Appearance

The least weasel appears particularly sleek and light, with a very blunt muzzle and small ears that seamlessly follows the overall shape without any notable protrusion from the rest. The tail seems to emphasize this, and is exceptionally thin and short. The limbs are also shorter in relation to the body than in other weasels, making them seem closer to the ground when in motion as if they are sliding rather than bounding.

Beyond this, there is really no “standard” look and it is necessary to mention a few subspecies to highlight their diversity:

M. n. rixosa– The least of the least, resembling infantile weasels in both size and proportion. Characterized by an elevated, rounded forehead and a stubby tail. Minimizing the outer extremities helps keeping them warm in a cold climate. White in winter.

M. n. nivalis– A small to medium-sized subspecies. Characterized by a short tail, dark reddish-brown fur and a straight, clean transition between the upper part and the white underside. White in winter.

M. n. vulgaris– The definite least weasel to many, especially in the UK where it is even known as the common weasel or simply THE weasel. Characterized by medium size around the length of a finger, longer tail than m. n. nivalis, light reddish-brown fur, spots on each cheek and a jagged transition between the upper part and the white underside.

M. n. numidica– The largest of the least hails from the Mediterranean basin, and is easily mistaken for a stoat and other larger weasel species. As a response to a warmer climate their outer extremities such as the tail and limbs have elongated, and the fur is a light shade of brown.

Winter coat

Their winter coat is the same as the stoat and the long-tailed weasel—slightly longer, very dense and white. Only certain subspecies native to colder climates undergo the moult cycle.

Habitat

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Behaviour

While all weasels are experts on hunting small rodents, the least weasel is more dependent on them than any other species. They do not seem to be as adaptive as the stoat when it comes to switching between various types of prey, and while they can hunt larger animals like rabbits and birds they do not do it nearly as often.

Reproduction

Unlike the stoat and the long-tailed weasel, the least weasel does not have delayed implantation, but they have their own way and can have up to two litters throughout the year. Being the finely tuned specialists that they are, this allows them to have better chances at benefiting from the sporadic growth in the small rodent populations. However, like the numbers of burrowing rodents tend to swing drastically between highs and lows, so does the number of least weasels, and they will not even produce young at all when the prey numbers are down.

Least weasels mate all year round, although it commonly takes place in early spring. The female is left to raise the kits on her own shortly after, and typically chooses to den in a hole dug by her rodent prey or in a hollow log, furnished with hair from a meal or the previous resident. A single litter consists of 4-10 young which are born blind and deaf, but grow quickly: By autumn that same year, the female kits are already sexually mature and ready to have their first litter!

Diet

Primarily rodents such as field- and water voles, but also rabbits, birds, eggs, insects and berries.

Predators

Geographic range

Body length: 13–26 cm / 5–10 in (males), 11.4–20.4 cm / 4.5–8.0 in (females)
Tail length: 1.2–8.7 cm / 0.5–3.4 in (males), 1.7–6 cm / 0.7–2.4 in (females)
Weight: 36–250 g / 1.3–8.8 oz (males), 29–117 g / 1.0–4.1 oz (females)
Lifespan: Up to 3 years (wild), up to 10 years (captivity)
Range: Widespread throughout the Northern Hemisphere.
Conservation status: Least concern
Subfamily: Mustelinae
Recognised subspecies(1)

  1. M. n. allegheniensis
  2. M. n. boccamela
  3. M. n. campestris
  4. M. n. caucasica
  5. M. n. eskimo
  6. M. n. heptneri
  7. M. n. mosanensis
  8. M. n. namiyei
  9. M. n. nivalis
  10. M. n. numidica
  11. M. n. pallida
  12. M. n. pygmaea
  13. M. n. rixosa
  14. M. n. rossica
  15. M. n. russelliana Classified as a distinct species by the IUCN.
  16. M. n. stoliczkana
  17. M. n. tonkinensis Classified as a distinct species by the IUCN.
  18. M. n. vulgaris
References
  1. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela nivalis in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#9 Long-Tailed Weasel (Mustela frenata)

Long-tailed weasel in summer coat by David Cooksy
Long-tailed weasel in winter coat by sdriscoll

The long-tailed weasel, also known as the bridled weasel, or sometimes misleadingly called a big stoat, is distributed from southern Canada throughout all the United States and Mexico, southward through all of Central America and into northern South America.

Appearance

Several species bear some resemblance to another, and the long-tailed weasel has a “look-alike cousin” in the stoat. Both have a black tail brush that serves the same function, both turn ermine in the North, and both overlap in size. By closer inspection, the characteristics are different in several aspects: Like the name suggests, the tail is notably longer, the ears are taller and the skull is less streamlined with a wider muzzle. When not in ermine, the long-tail’s colours and contrasting facial markings sported by some of the subspecies in dark brown and white can easily help as an identification factor.

Overall they are a warm shade of sandy-brown on top, yellow to orange-buff below and sports white paws, but due to their wide distribution, the markings and colour depth have an impressive variation. Some do not have facial markings at all, and the so-called bridled weasel (subspecies: M. f. xanthogenys) from California is perhaps the most recognizable of them all, having been nicknamed for their bridle-like mask. The intensity of the pigmentation is caused by the level of humidity in an area, a phenomenon called Gloger’s rule.

Winter coat

Their winter coat is the same as the least weasel and the stoat—slightly longer, very dense and white. Only certain subspecies native to colder climates undergo the moult cycle. The tip of the tail always remains black.

Habitat

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Behaviour

The majority of the weasels are strictly solitary and polygamous, with the female having the responsibility for raising the young, while the males travel long distances to mate with as many females as possible. The long-tailed weasel is not an exception to the rule, but the male has been known to show a little more hospitality than just leaving the family to themselves after he has done his work. Like the stoat, the male long-tail will occasionally bring “gifts” in the form of caught prey to the den, most likely in attempt to calm the defensive aggression of the nesting female and thus gain access to mate with her. The difference is that the male long-tail does this more frequently, and because the females have to do some growing before they are sexually mature, investing in providing for them may help their survival and increase the numbers of potential mates.(1)

Reproduction

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Diet

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Predators

Geographic range

Body length: 33–42 cm / 13–16.5 in (males), 28–35.5 cm / 11–14 in (females)
Tail length: 13.2–29.4 cm / 5–11.5 (males), 11.2–24.5 cm / 4.5–9.5 (females)
Weight: 226–401 g / 8–14.6 oz (males), 130–178 g / 4.5–6 oz (females)
Lifespan: Unknown (wild), up to 9 years (captivity)
Range: Southern Canada, all of the United States and Mexico, Central America and northern South America.
Conservation status: Least concern
Subfamily: Mustelinae
Recognised subspecies(2)

  1. M. f. affinis
  2. M. f. agilis
  3. M. f. alleni
  4. M. f. altifrontalis
  5. M. f. arizonensis
  6. M. f. arthuri
  7. M. f. aureoventris
  8. M. f. boliviensis
  9. M. f. costaricensis
  10. M. f. effera
  11. M. f. frenata
  12. M. f. goldmani
  13. M. f. gracilis
  14. M. f. helleri
  15. M. f. inyoensis
  16. M. f. latirostra
  17. M. f. leucoparia
  18. M. f. longicauda
  19. M. f. macrophonius
  20. M. f. munda
  21. M. f. neomexicanus
  22. M. f. nevadensis
  23. M. f. nicaraquae
  24. M. f. nigriauris
  25. M. f. notius
  26. M. f. noveboracensis
  27. M. f. occisor
  28. M. f. olivacea
  29. M. f. oregonensis
  30. M. f. oribasus
  31. M. f. panamensis
  32. M. f. peninsulae
  33. M. f. perda
  34. M. f. perotae
  35. M. f. primulina
  36. M. f. pulchra
  37. M. f. saturata
  38. M. f. spadix
  39. M. f. texensis
  40. M. f. tropicalis
  41. M. f. washingtoni
  42. M. f. xanthogenys
References
  1. Jr., Hamilton & Gamble, King, Carolyn & Powell, Roger, The Natural History of Weasels and Stoats: Ecology, Behaviour and Management,  2nd ed., Oxford University Press, 2007, Oxford, p.357.
  2. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela frenata in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#10 Malayan Weasel (Mustela nudipes)

Photo by Stefanie De Win

The Malayan weasel, also known as the bare-footed weasel, lives in Southeast Asia. They can be found in Brunei, Indonesia, Malaysia, and Thailand—on the islands of Sumatra and Borneo, and the southern half of the Malay Peninsula.

Appearance

Perhaps one of the most aesthetically pleasing species in terms of colouration, with a pure white head in stark contrast to the overall warm palette, with a golden brown body, orange-buff bib (throat and chest patch) and one third of the tail pale buff to white, matching the light head. The Malayan weasel’s alternate- as well as their scientific name nudipes, accurately describes one of their most striking characteristics- that the soles around the paw pads are entirely hairless, although the purpose of this characteristic is unknown. Furthermore, the Malayan weasel has a somewhat shaggy appearance compared to the short and glossy coat of most weasels.

They are often confused with the Japanese marten because of their similar, pale-furred face.

Habitat

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Behaviour

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Reproduction

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Diet

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Predators

Geographic range

Body length: 30–36 cm / 12–14 in
Tail length: 24–26 cm / 9.4–10.2 in
Weight: 598 g / 20.8 oz
Lifespan: Unknown (wild), unknown (captivity)
Range: The Sundaic sub-region of Southeast Asia.
Conservation status: Least concern
Subfamily: Mustelinae
Recognised subspecies(1)

  1. M. n. leucocephalus
  2. M. n. nudipes
References
  1. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela nudipes in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#12 Stoat / Short-Tailed Weasel (Mustela erminea)

Stoat in summer coat by Charlie Marshall
Stoat in winter coat by jschweg

The stoat, also known as the short-tailed weasel in North American English, or ermine when in their white winter coat, is native throughout much of the Northern Hemisphere. They are found across Europe, Asia and North America.

Appearance

During the summer months stoats are russet in colour on the head and dorsal surface, with off-white underparts that run from the chin to along the abdomen, and have a distinguished black-tipped tail. The black brush that helps us telling the stoat apart from any other species is not only eye-catching to a human observer, it has evolved to function as a decoy to distract predators; especially birds of prey. This becomes even more efficient in winter, when northern weasels turn ermine: against the white background and when seen from above, ermines will appear like a flashing, dark dot thanks to their tail, keeping the pursuer from attacking the more vital parts of the body.

Winter coat

Their winter coat is the same as the least weasel and the long-tailed weasel—slightly longer, very dense and white. During the winter months when temperatures drop and the nights become longer, certain subspecies of stoat native to colder climates moult into their white winter coat. The tip of the tail always remains black.(1)

Albino stoats

On rare occasions, a stoat can be born albino. The difference between an albino stoat and one that is in ermine, is that an albino stoat will have pink/red eyes, and no black-tipped tail. They would be seen in their white coats all year round, making them more vulnerable to predators when there is little to no snow about for natural camouflage.

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Reproduction

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Diet

Aside from birds and rabbits, stoats prey on rodents, fish, eggs, insects, small reptiles and amphibians.(2)

Predators

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Fur use

The white winter fur of stoats has long been used in trimming coats and making stoles. This fur is referred to as “ermine”, and is the ancient symbol of the Duchy of Brittany; forming the earliest flag of that nation. Historically throughout Europe, ermine fur was considered to be a symbol of royalty and high status. However, due to animal rights concerns, faux fur is becoming more widely used; decreasing the demand for ermine pelts.(2)

Introduction to New Zealand

Stoats are known for taking down prey more than five times their size—using their sharp teeth to bite into the necks of larger animals such as rabbits. For this skill, during the 1870s and 1880s stoats were introduced to New Zealand to control the growing rabbit population. This act may have proved effective for the time, but it has since only resulted in a devastating effect on the native bird population today,(3) prompting the New Zealand government to take action in eradicating them in their Predator Free 2050 programme.(4) Stoats are increasingly portrayed as vicious vermin that prey upon helpless birds, but it was humans who deliberately introduced to the region. This is why we must always be cautious about introducing a foreign species to a new environment.

Common names (an identity crisis)

Ermine: In the English language “ermine” is a term used to refer to the stoat’s white winter coat, not the animal itself. A stoat is being “in ermine” or “in their ermine coat” while white. They are also one of few mustelids whose species’ scientific epithet is similar to its common name. Some other creatures are also referred to as ermine when sporting a black and white colouration, such as ermine moths (Family: Yponomeutidae).

Stoat vs. short-tailed weasel: The stoat is called a “short-tailed weasel” in North America, while “stoat” is preferred by the rest of the English-speaking world. The stoat is also simply called a weasel in Ireland where the least weasel is not known to live.

The “stoats and weasels” phrase: It is unclear why in England and New Zealand we continue to call one weasel a stoat, while the other is simply called a weasel. The phrase “stoats and weasels” is commonly used when a stoat IS a weasel. This phrase can be confusing for those not aware “weasel” is often used as a generic term to refer to the least weasel in these two countries. We have found that even some people who are raised in these nations are not aware of what “weasel” really means. When referring to these two mustelids in the same context, “stoats and least weasels” would ultimately provide better clarity, especially for an international audience. If you have ever read The Wind in the Willows, Redwall, or Welkin Weasels and could not understand why some weasel-like species were called stoats, while other species with near similar features were just called weasels, now you know! We were confused too.

In social media

In recent years, wildlife artist Robert E. Fuller’s video footage of stoats and least weasels from surveillance cameras on his property have gone viral on many social discussion platforms. Perhaps the most well-known of these videos feature a group of young stoats bouncing about on a blue trampoline. As usual with viral videos, few users give attribution to the original creator, so we wanted our readers to know one of the main sources for great stoat surveillance. Among being an artist, Mr. Fuller has a deep appreciation for these mustelids and tries to educate the public about them. He is also known for raising and documenting a couple of orphaned stoats he named Whisper and Stuart, as well as least weasels by the names Fidget, Ron, and Twiz.

Geographic range

Body length: 25–35 cm / 10–14 in (males), 17–27 cm / 6–10 in (females)
Tail length: 7.5–12 cm / 3.0–4.7 in (males), 6.5–10.6 cm / 2.6–4.2 in (females)
Weight: 67–450 g / 2.3–15.8 oz (males), 25–260 g / 0.8–9 oz (females)
Lifespan: Up to 5 years (wild), up to 10 years (captivity)
Range: Widespread throughout the Northern Hemisphere and introduced to New Zealand.
Conservation status: Least concern
Subfamily: Mustelinae
Recognised subspecies(5)

  1. M. e. aestiva
  2. M. e. alascensis
  3. M. e. anguinae
  4. M. e. arctica
  5. M. e. augustidens
  6. M. e. bangsi
  7. M. e. celenda
  8. M. e. cigognanii
  9. M. e. erminea
  10. M. e. fallenda
  11. M. e. ferghanae
  12. M. e. gulosa
  13. M. e. haidarum
  14. M. e. hibernica
  15. M. e. initis
  16. M. e. invicta
  17. M. e. kadiacensis
  18. M. e. kaneii
  19. M. e. karaginensis
  20. M. e. lymani
  21. M. e. martinoi
  22. M. e. minima
  23. M. e. mongolica
  24. M. e. muricus
  25. M. e. nippon
  26. M. e. ognevi
  27. M. e. olympica
  28. M. e. polaris
  29. M. e. richardsonii
  30. M. e. ricinae
  31. M. e. salva
  32. M. e. seclusa
  33. M. e. semplei
  34. M. e. stabilis
  35. M. e. streatori
  36. M. e. teberdina
  37. M. e. tobolica
References
  1. Harris, S., and D. W. Yalden. “Mammals of the British Isles, 4th edn (Southampton: Mammal Society).” (2008). p. 457.
  2. Loso, H. 1999. Mustela erminea (On-line), Animal Diversity Web. Accessed April 28, 2020.
  3. King, Carolyn Immigrant killers: introduced predators and the conservation of birds in New Zealand. Oxford University Press, 1984.
  4. Linklater, Wayne, and Jamie Steer. Predator Free 2050: A flawed conservation policy displaces higher priorities and better, evidence‐based alternatives. Conservation Letters 11.6 (2018): e12593.
  5. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela erminea in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#13 Yellow-Bellied Weasel (Mustela kathiah)

Photo by jbhatia

The yellow-bellied weasel is found in Bhutan, Burma, China, India, Laos, Nepal, Pakistan, Thailand and Vietnam.(1)

Appearance

The species is named for the deep yellow-coloured underbelly, while the rest of the pelt is dark brown. The upper lip, chin and throat are a lighter yellow-white colour.

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Diet

Yellow-bellied weasels prefer to consume mice, rats, voles and other small mammals. They will also prey on birds.(2)

Predators

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Benefits to humans

The Nepalese have been known to keep yellow-bellied weasels as pets to manage rodent populations in their homes. It is also reported that they have even been trained to attack geese, goats, and sheep for sport.(2)(3)(4)

Geographic range

Body length: 25.0–27.0 cm / 9.84–10.63 in
Weight: 1,560 g / 55 oz
Lifespan: Unknown (wild), unknown (captivity)
Range: Central and eastern Asia.
Conservation status: Least concern
Subfamily: Mustelinae
Recognised subspecies(5)

  1. M. k. caporiaccoi
  2. M. k. kathiah
References
  1. “Yellow-bellied weasel”Thai National Parks.
  2. Bandner, K. 2002. Mustela kathiah (On-line), Animal Diversity Web. Accessed February 07, 2021.
  3. Jha, A. “Status of the weasel family in Sikkim.” Tigerpaper (FAO) (1999).
  4. Sterndale, Robert Armitage. Natural history of the Mammalia of India and Ceylon. Thacker, Spink, 1884.
  5. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela kathiah in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#14 African Striped Weasel (Poecilogale albinucha)
This species shares the common name “weasel”, but is not directly related to other species on this page except for L. patagonicus.

Photo by Devonpike

The African striped weasel is native to sub-Saharan Africa, and is one of the smallest carnivores on the continent.

Appearance

It is black and white (or yellowish) in colour and closely resembles a skunk.

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Reproduction

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Diet

Their diet consists of rodents, young birds, reptiles, and insects on occasion.

Predators

Geographic range

Body length: 27–32 cm / 11–3 in
Tail length: 16–20 cm / 6.3–7.9 in
Weight: 339 g /12.0 oz (males),  251 g / 8.9 oz (females)
Lifespan: Unknown (wild), up to 5 years (captivity)
Range: Much of Africa south of the equator.
Conservation status: Least concern
Subfamily: Ictonychinae
References

#15 Patagonian Weasel (Lyncodon patagonicus)
This species shares the common name “weasel”, but is not directly related to other species on this page except for P. albinucha.

Photo by Darío Podestá

The Patagonian weasel is the only member of the genus Lyncodon,(1) and is one of the least known mustelids in South America.

Appearance

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Habitat

Very little is known about this species habitat, but they can be found in both southern Argentina and southeastern Chile. They supposedly inhabit herbaceous and shrub steppes in arid and semiarid areas.(2)

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Reproduction

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Diet

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Predators

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Benefits to humans

The Patagonian weasel has been reported to be trained by some local ranchers to hunt and trap small terrestrial animals; mainly rodents.(3)

Geographic range

Body length: 30–35 cm / 12–14 in
Weight: 225 g / 7,93 oz
Lifespan: Unknown (wild), unknown (captivity)
Range: Southern Argentina and southeastern Chile.
Conservation status: Least concern
Subfamily: Ictonychinae
Recognised subspecies(4)

  1. M. k. caporiaccoi
  2. M. k. kathiah
References
  1. Wilson, Don E., and DeeAnn M. Reeder, eds. Mammal species of the world: a taxonomic and geographic reference. Vol. 1. JHU Press, 2005.
  2. Schiaffini, Mauro I., et al. Distribution of Lyncodon patagonicus (Carnivora, Mustelidae): changes from the Last Glacial Maximum to the present. Journal of Mammalogy 94.2 (2013): 339-350.
  3. Malek, K. 2003. Lyncodon patagonicus (On-line), Animal Diversity Web. Accessed February 07, 2021.
  4. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Lyncodon patagonicus in Mammal Species of the World. – A Taxonomic and Geographic Reference.

What Are Mustelids?

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