Old World Weasels

The term Old World weasels is not officially recognised, but we decided to use it in contrast to the New World Weasels page. The weasels included on this page are simply those that were not reclassified into the genus Neogale.(1)(2)

References

  1. Patterson, Bruce D., et al. On the nomenclature of the American clade of weasels (Carnivora: Mustelidae)“. Journal of Animal Diversity 3.2 (2021): 1-8.
  2. “Explore the Database”. www.mammaldiversity.org. Accessed 01 September, 2021.

#1 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)(3)

Behaviour

Like many weasels, the back-striped weasels are presumed to be diurnal and mostly solitary.(3)

Reproduction

.

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

.

Conservation

The back-striped weasel is protected in Thailand and listed as Endangered on the China Red List.(4)(5)

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. Oo, Sai Sein Lin, et al. A recent sighting of the Stripe-backed Weasel Mustela strigidorsa (Mammalia: Carnivora: Mustelidae) in Hkakabo Razi Landscape, Myanmar. Journal of Threatened Taxa 13.12 (2021): 19855-19859.
  4. Roberton, S., et al. “Mustela strigidorsa. The IUCN Red List of Threatened Species 2016: e. T14027A45201218.” (2016).
  5. Wang, S. and Xie, Y. 2004. China Species Red List. Vol. 1 Red List. Higher Education Press, Beijing, China.

#2 Eurasian Stoat (Mustela erminea)

Eurasian stoat in summer coat by Charlie Marshall
Eurasian stoat in winter coat by svetlanaagafonova

The Eurasian stoat, also known as the Beringian stoat, short-tailed weasel, ermine when in their winter coat, or simply stoat, is native throughout much of Eurasia and the northern portions of North America.

For many years M. erminea was considered to be the one and only stoat species, until a 2021 study found two subspecies of M. erminea (the North American stoat and Haida stoat) to be distinct species.(1)(2) Since M. erminea now mostly refers to stoats native to Eurasia, this species is becoming known as the Eurasian stoat. The Tundra stoat (M. e. arctica), Kodiak stoat (M. e. kadiacensis), Polar stoat (M. e. polaris), and (M. e. salva) appear to be the only subspecies of the Eurasian stoat found in North America under the current proposed revised taxonomy.(1)

Appearance

During the summer months Eurasian stoats are russet in colour on the head and dorsal surface, with off-white (sometimes yellowish) 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 Eurasian stoat apart from any other weasel species in Eurasia 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 (referred to as “ermine”) is the same as the one found in the North American stoat, Haida stoat, least weasel, and long-tailed weasel. When temperatures drop and the nights become longer, certain subspecies of Eurasian stoat native to colder climates moult into their white winter coat. The tip of the tail always remains black.(3)

Albino Eurasian stoats

On rare occasions, a Eurasian stoat (like all other stoats and many other animals) can be born albino. The difference between an albino stoat and one that is in ermine, is that an albino one will have pink/red eyes, a pink nose, and typically 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.

To the untrained eye, an albino stoat can easily be confused for an albino ferret. To differentiate these two, stoats are smaller and slimmer overall, and have larger paws in relation to their size. Ferrets have boxy muzzles and skulls, pear-shaped bodies (in comparison) and coarser fur, especially on the back. Ferret tails are shorter, tapering towards the tip and without the tail brush that stoats have. Ferrets also tend to arch their backs more when they move about.

Habitat

.

Behaviour

.

Reproduction

.

Diet

Aside from birds and rabbits, Eurasian stoats prey on rodents, fish, eggs, insects, small reptiles and amphibians.(4)

Predators

.

Possible declining numbers in North America

While there is currently no widespread conservation effort for the Eurasian stoat, a recent study suggests that their numbers could be declining in some parts of North America.(5)

Fur use

The white winter fur of Eurasian 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 and decreasing the demand for ermine pelts.(4)

Introduction to New Zealand

Eurasian stoats are known for taking down prey more than five times their size—using their teeth to bite into the necks of larger animals such as rabbits. For this skill, during the 1880s, Eurasian stoats were introduced to New Zealand in hopes of controlling the growing rabbit population. This may have seemed like a good idea to some at the time, but this decision has had a devastating effect on the native bird population,(6)(7) prompting the New Zealand government to take action in eradicating them in their Predator Free 2050 programme.(8) Eurasian 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 in English (an identity crisis)

Since the introduction of the two new distinct stoat species the North American stoat and Haida stoat, the common names for these mustelids have become even more confusing, especially since there is little consistency among scientists on whether to refer to them as stoats, ermine, or less often, short-tailed weasels. By far “stoat” is the most common English name for these animals.

Ermine

In the English language “ermine” is usually a term used to refer to any of the three species of stoat when in their white winter coat or pelt thereof, rather than the animal itself. Given this association, it confuses some people when a stoat is called an ermine even while in their brown summer coat. We have occasionally come across the phrase “white ermine” when a stoat is in its winter coat, which to some can sound tautologic. Some other creatures are also referred to as ermine when sporting a black and white colouration such as ermine moths (Family: Yponomeutidae).

Stoat versus short-tailed weasel

Stoats are called “short-tailed weasels” in North American English (though we rarely hear this, since the average person often refers to them as stoats) while “stoat” is preferred by the rest of the English-speaking world. The Eurasian 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 vague 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 English literature such as 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 similar features were just called weasels, now you know! We were confused too. Just remember that least weasels in the UK (subspecies: M. n. vulgaris) are smaller than Eurasian stoats in the UK (subspecies: M. e. stabilis). They also do not have dark-tipped tails and do not change white for winter.

In social media

In recent years, wildlife artist Robert E. Fuller’s video footage of Eurasian 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 Eurasian 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 Eurasian 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 Eurasian 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 North America, Eurasia, and introduced to New Zealand.
Conservation status: Least concern
Subfamily: Mustelinae
Recognised subspecies(1)(9)

  1. Middle Russian stoat — M. e. aestiva
  2. Tundra stoat — M. e. arctica
  3. M. e. augustidens
  4. Northern stoat — M. e. erminea
  5. Fergana stoat — M. e. ferghanae
  6. Irish stoat — M. e. hibernica
  7. Kodiak stoat — M. e. kadiacensis
  8. East Siberian stoat (known locally as Ezo stoat in Japan) — M. e. kaneii
  9. Karaginsky stoat — M. e. karaginensis
  10. Altai stoat — M. e. lymani
  11. M. e. martinoi
  12. Swiss stoat — M. e. minima
  13. Gobi stoat — M. e. mongolica
  14. Japanese stoat — M. e. nippon
  15. M. e. ognevi
  16. Polar stoat — M. e. polaris
  17. Hebrides stoat — M. e. ricinae
  18. M. e. salva
  19. British stoat — M. e. stabilis
  20. Caucasian stoat — M. e. teberdina
  21. Tobolsk stoat — M. e. tobolica
References
  1. Colella, Jocelyn P., et al. Extrinsically reinforced hybrid speciation within Holarctic ermine (Mustela spp.) produces an insular endemic. Diversity and Distributions 27.4 (2021): 747-762.
  2. “Distinct Species of Adorable Weasels Have Been Hiding in Plain Sight”. Gizmodo. Retrieved 2021-07-12.
  3. Harris, S., and D. W. Yalden. “Mammals of the British Isles, 4th edn (Southampton: Mammal Society).” (2008). p. 457.
  4. Loso, H. 1999. Mustela erminea (On-line), Animal Diversity Web. Accessed April 28, 2020.
  5. Jachowski, David, et al. Tracking the decline of weasels in North America. PloS one 16.7 (2021): e0254387.
  6. King, Carolyn Immigrant killers: introduced predators and the conservation of birds in New Zealand. Oxford University Press, 1984.
  7. King, Carolyn M., and Roger A. Powell. The Natural History of Weasels and Stoats: Ecology, Behavior, and Management. Oxford University Press, 2006. Chapter 13.
  8. 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.
  9. “Explore the Database”. www.mammaldiversity.org. Accessed 10 September, 2021.

#3 Haida Stoat (Mustela haidarum)

Haida stoat in winter coat by the USDA Forest Service Northern Region

The Haida stoat, also known as the short-tailed weasel, ermine when in their winter coat, or simply stoat, is endemic to a few islands off the Pacific Northwest of North America, namely Haida Gwaii in Canada and the southern Alexander Archipelago in the U.S. state of Alaska. This species is more commonly called the Haida ermine in the articles we reference, but we will not be referring to them as such on this site. When used in English, “ermine” usually refers to stoats when in their white winter coat or pelt thereof. We feel it creates confusion when the term ermine is used to refer to the species itself, especially when they are in their brown summer coat.

The three subspecies comprising the Haida stoat were originally considered subspecies of Eurasian stoat, but in 2013 they were recognised as distinct from any other stoat after examining their DNA and skull. Later, a 2021 study found them to together comprise a distinct species. The Haida stoat is presumed to have originated about 375,000 years ago, and is thought to be a result of hybrid speciation between the Eurasian stoat and North American stoat. The islands of Haida Gwaii and Prince of Wales are thought to have been glacial refugia during the Last Glacial Maximum, with both species of stoat being isolated on the islands and hybridising with one another while the ice sheets isolated them from the rest of the world—leading to the formation of a new species.(1)(2)(3)

Appearance

The Haida stoat can be superficially distinguished from the North American and Eurasian stoat by their elongated skull.(2)

Winter coat

Their winter coat (referred to as “ermine”) is the same as the one found in the North American stoat, Eurasian stoat, least weasel, and long-tailed weasel. The tip of the tail always remains black.

Habitat

.

Behaviour

.

Reproduction

.

Diet

.

Geographic range

Body length: N/A
Tail length: N/A
Weight: N/A
Lifespan: Unknown (wild), unknown (captivity)
Range: Haida Gwaii in Canada and the southern Alexander Archipelago in the U.S. state of Alaska.
Conservation status: Imperiled (haidarum), Vulnerable (celenda and seclusa)
Subfamily: Mustelinae
Recognised subspecies(1)

  1. Prince of Wales Island stoat — M. h. celenda
  2. Haida stoat — M. h. haidarum
  3. Suemez Island — M. h. seclusa
References
  1. Colella, Jocelyn P., et al. Extrinsically reinforced hybrid speciation within Holarctic ermine (Mustela spp.) produces an insular endemic. Diversity and Distributions 27.4 (2021): 747-762.
  2. Denning, Angela. KFSK- Petersburg. 30 March, 2021. “New ermine species found on Southeast Alaska island”. Alaska Public Media. Accessed 13 September, 2021.
  3. Yahoo News Canada. 12 April, 2021. “Scientists discover hybrid ermine species isolated in Haida Gwaii for 300,000 years”. Accessed 13 September, 2021.

#4 Indonesian Mountain Weasel (Mustela lutreolina)

Photo by Ahmad Mursyid

The Indonesian mountain weasel is a species that lives in highlands on the islands of Java and Sumatra, Indonesia. They are island endemic and native to the Oriental biogeographic region.(1)

Appearance

Being relatively large with an overall dark brown exterior, a bushy tail and partially webbed paws, this weasel can easily be mistaken for a North American mink or European mink. They are however, lighter in build than either of those species, and have larger eyes and ears in proportion to the skull.

Their markings are also a bit different in shape and colour and can be distinguished by contrasting light yellow upper lip patches, chin and a throat patch that extends down the throat. The patch 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. The webbing indicate some affinity for water.

Behaviour

.

Reproduction

.

Diet

.

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

  1. Duckworth, J.W., Holden, J., Eaton, J., Meijaard, E., Long, B. & Abramov, A.V. 2016. Mustela Lutreolina (On-line). IUCN Red List. Accessed 26 April, 2022.

#5 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 specialised of all the weasels. In England and New Zealand the least weasel is often simply called a “weasel”.(1)

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 Eurasian stoat or other larger weasel species. As a response to the 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 similar to the North American stoat’s, Eurasian stoat’sHaida stoat’s and long-tailed weasel’s—slightly longer than the summer coat and very dense and white, minus the black-tipped tail. Only certain subspecies native to colder climates undergo the moult cycle. Unlike stoats, they are usually not called ermine while in their winter coat.

Habitat

.

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

.

Introduction to New Zealand

.

Possible declining numbers in North America

While there is currently no widespread conservation effort for the least weasel in North America, a recent study has found that their numbers appear to be declining at a concerning rate in some parts of the continent.(2)

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(3)

  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 — Formerly thought to be a distinct species, the Egyptian weasel.
  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. King, Carolyn M., and Roger A. Powell. The Natural History of Weasels and Stoats: Ecology, Behavior, and Management. Oxford University Press, 2006. p. 12.
  2. Jachowski, David, et al. Tracking the decline of weasels in North America. PloS one 16.7 (2021): e0254387.
  3. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela nivalis in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#6 Malay Weasel (Mustela nudipes)

Photo by Luke Mackin

The Malay weasel, also known as the Malayan weasel or bare-footed weasel, is confined to three large land-masses of Sundaic Southeast Asia—the Thai-Malay peninsula, and the islands of Sumatra and Borneo.(1)

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 Malay 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 Malay 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

.

Behaviour

.

Reproduction

.

Diet

.

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(2)

  1. M. n. leucocephalus
  2. M. n. nudipes
References
  1. Duckworth, J.W., Chutipong, W., Hearn, A. & Ross, J. 2015. “Mustela nudipes. The IUCN Red List of Threatened Species 2015: e.T41657A45214257. Accessed 24 May 2021.
  2. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mustela nudipes in Mammal Species of the World. – A Taxonomic and Geographic Reference.

#7 Mountain Weasel (Mustela altaica)

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

The mountain weasel, also known as the Altai weasel, pale weasel, or solongoi, primarily lives in high-altitude regions of Asia. DNA analyses reveal they are the closest relative of the Eurasian 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.

Winter coat

A darker shade and more contrastful than the summer coat.

Habitat

.

Behaviour

.

Reproduction

.

Diet

The mountain weasel is 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.

#8 North American Stoat (Mustela richardsonii)

Supposedly a North American stoat in summer coat by Steve Hillebrand
Supposedly a North American stoat in winter coat by jschweg

The North American stoat, also known as the American stoat, short-tailed weasel, ermine when in their winter coat, or simply stoat, is a species native to most of North America. This species is also called the American ermine in the articles we reference, but we will not be referring to them as such on this site. When used in English, “ermine” usually refers to stoats when in their white winter coat or pelt thereof. We feel it creates confusion when the term ermine is used to refer to the species itself, especially when they are in their brown summer coat.

This species was long considered a subspecies of the Eurasian stoat, until a 2021 study found them to be a distinct species, forming distinct genetic clades from erminea.(1)(2) Despite their name, Eurasian stoats can still be found in North America, and it is difficult to distinguish between the two species.

Appearance

.

Winter coat

Their winter coat (referred to as “ermine”) is the same as the one found in the Eurasian stoat, Haida stoat, least weasel, and long-tailed weasel. The tip of the tail always remains black.

Habitat

.

Behaviour

.

Reproduction

.

Diet

.

Possible declining numbers

While there is currently no widespread conservation effort for the North American stoat, a recent study suggests that their numbers could be declining in some parts of North America.(3)

Geographic range

Body length: N/A
Tail length: N/A
Weight: N/A
Lifespan: Unknown (wild), unknown (captivity)
Range: Most of North America
Conservation status: Not evaluated
Subfamily: Mustelinae
Recognised subspecies

  1. Junean stoat — M. r. alascensis
  2. Vancouver Island  stoat — M. r. anguinae
  3. Western Great Lakes stoat — M. r. bangsi
  4. Bonaparte’s stoat — M. r. cigognanii
  5. M. r. fallenda
  6. M. r. gulosa
  7. M. r. initis
  8. M. r. invicta
  9. Southwestern stoat — M. r. muricus
  10. Olympic stoat — M. r. olympica
  11. Richardson’s stoat — M. r. richardsonii
  12. Baffin Island stoat — M. r. semplei
  13. M. r. stratori
References
  1. Colella, Jocelyn P., et al. Extrinsically reinforced hybrid speciation within Holarctic ermine (Mustela spp.) produces an insular endemic. Diversity and Distributions 27.4 (2021): 747-762.
  2. “Distinct Species of Adorable Weasels Have Been Hiding in Plain Sight”. Gizmodo. Retrieved 2021-07-12.
  3. Jachowski, David, et al. Tracking the decline of weasels in North America. PloS one 16.7 (2021): e0254387.

#9 Yellow-Bellied Weasel (Mustela kathiah)

Photo by jbhatia
Alternate photo: Link

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.

Habitat

.

Behaviour

.

Reproduction

.

Diet

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

Predators

.

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.

#10 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 on the continent. They can be found as far north as the Democratic Republic of the Congo and Kenya to as far south as southern South Africa.

Appearance

The African striped weasel has a short and broad snout and short ears. Their claws are curved. The top of the head is white, which continues downward as a broad stripe where there are black and white to pale yellowish stripes running down the back, the tail is completely white. As with most mustelids, males are larger than females.(1) They are sometimes confused with the striped polecat.

Habitat

They can be found in a variety of habitats such as forests, grasslands, and marsh regions, but are most commonly found in savannahs. They usually live below 1,500 m (4,900 ft) elevation, but may be found as high as 2,200 m (7,200 ft).(2)(3)

Behaviour

The African striped weasel is nocturnal and lives primarily underground, though they may sometimes be found resting in hollow logs or rock crevices. Although mostly solitary, individuals will sometimes pair together to dig burrows. Sometimes they will take over the burrows of other animals such as rodents or mounds made by termites and modify them to suit their needs. The burrow varies in length but always has a rounded chamber where prey is cached for later consumption. The African striped weasel only leaves its burrow to hunt, and always brings kill back into the den before consuming or caching it. They kill prey by attacking the back of the neck then whipping their own bodies and kicking to stun and tear animal.(4)(5)

Males are aggressive towards the same sex, and will fluff their tails, make short cries and fake charges before the encounter escalates to fighting with bites, shaking, and aggressive shrieks if neither individual retreats.(1) Although a mostly silent animal, they have been known to have different vocalisations for distress, threat, defense, and greeting.(6)

Reproduction

Males may mate at 33 months of age and females may have their first litter at 19 months. Mating season is in the spring and summer, and includes three bouts of copulation lasting between 60 to 80 minutes each in a single 24 hour period.(1)(7) The gestation period lasts around 30 days and litters consists of 1-3 young.(1) The young are initially blind and hairless. They are fully weaned at about 11 weeks and reach adult size at 20 weeks. They are sexually mature by 8 months.(7)

Diet

Their diet consists of rodents, young birds, reptiles, and insects on occasion.(3)(4)(8) Captive individuals have been observed to usually not eat the head, tail, legs, and dorsal skin of larger rodents.(6)

Predators

Poorly known. Presumably preyed upon by owls.(9)

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

  1. Larivière, Serge. Poecilogale albinucha. Mammalian species 2001.681 (2001): 1-4.
  2. Stuart, C., M. Stuart, and E. Do Linh San. Poecilogale albinucha. The IUCN Red List of Threatened Species 2015: e. T41662A45215258. (2015).
  3. Nowak, Ronald M., and Ernest Pillsbury Walker. “Walker’s Mammals of the World”. Vol. 1. JHU press, 1999.
  4. Rowe-Rowe, D. T. “Comparative prey capture and food studies of South African mustelines”. (1978): 175-196.
  5. Kingdon, Jonathan. “East African Mammals”. pt. A. Carnivores. Vol. 3. Academic Press, 1977.
  6. Channing, Alan, and D. T. Rowe‐Rowe. “Vocalizations of South African mustelines”. Zeitschrift für Tierpsychologie 44.3 (1977): 283-293.
  7. Rowe-Rowe, D. T. “Reproduction and post-natal development of South African mustelines (Carnivora: Mustelidae)”. African Zoology 13.1 (1978): 103-114.
  8. Smithers, R. H. N. “The mammals of Rhodesia, Zambia and Malawi. Collins, London. 1971. The mammals of Botswana”. Nat. Mus. of Rhodesia. Memoir 4 (1966).
  9. Brilliant, T. 2000. Poecilogale albinucha“. (On-line), Animal Diversity Web. Accessed 14 May, 2022.

#11 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
Alternate photo: Link 1

The Patagonian weasel is the only member of the genus Lyncodon,(1) and is one of the least known mustelids in South America. Its range is from the southern and western parts of Argentina into sections of Chile.(2)

Appearance

The fur is usually whiteish with some blended dark brown and black tones. There is a broad white to yellowish stripe that runs from the head along its neck and sides. As with most weasel-like mustelids, they have small ears, short legs, and a long body.

Habitat

Very little is known about their habitat. They supposedly inhabit herbaceous and shrub steppes in arid and semiarid areas.(2) Another source suggests they are found in Pampas habitats that have light-coloured substrates excluding deserts.(3)

Behaviour

The Patagonian weasel is has been reported to only be active at dusk and night. When cornered, the neck pelage will be erected as a defensive warning.(3)

Reproduction

The reproductive behaviour of this species is unknown.

Diet

Little is known about the Patagonian weasel’s diet, but they have been known to enter burrows of Ctenomys and Microcavia species, suggesting that may be their prey.(3)

Predators

Predation on this species has not been reported.

Benefits to humans

The Patagonian weasel has been reported to be trained by some local ranchers to hunt and trap small terrestrial animals.(4)

Geographic range

Head and body length: 30–35 cm / 12–14 in
Tail length: 6–9 cm / 2.4–3.5 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(1)

  1. L. p. patagonicus
  2. L. p. thomasi
References
  1. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Lyncodon patagonicus in Mammal Species of the World. – A Taxonomic and Geographic Reference.
  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. Nowak, Ronald M., and Ernest Pillsbury Walker. Walker’s Mammals of the World. Vol. 1. JHU press, 1999.

Old World Weasels | New World Weasels | Polecats

What Are Mustelids?

Badgers | Ferret-Badgers | Fisher | Grisons | Martens | OttersTayra | Weasels | Wolverine