The Mustelidae (/ˌmʌˈstɛlɪdi/; from Latin mustela, weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, mink, and wolverines, among others. Mustelids /ˈmʌstəlɪd/ are diverse and the largest family in the order Carnivora, suborder Caniformia. Mustelidae comprises about 56-60 species across eight subfamilies.
G. Fischer de Waldheim, 1817
Mustelids vary greatly in size and behaviour. The least weasel can be under a foot in length, while the giant otter can measure up to 1.7 m (5 ft 7 in) and sea otters can exceed 45 kg (99 lb) in weight. The wolverine can crush bones as thick as the femur of a moose to get at the marrow, and has been seen attempting to drive bears away from their kills. The sea otter uses rocks to break open shellfish to eat. The marten is largely arboreal, while the European badger digs extensive networks of tunnels, called setts. Some mustelids have been domesticated: the ferret and the tayra are kept as pets (although the tayra requires a Dangerous Wild Animals licence in the UK), or as working animals for hunting or vermin control. Others have been important in the fur trade—the mink is often raised for its fur.
As well as being one of the most species-rich families in the order Carnivora, the family Mustelidae is one of the oldest. Mustelid-like forms first appeared about 40 million years ago, roughly coinciding with the appearance of rodents. The direct ancestors of the modern mustelids first appeared about 15 million years ago.
Within a large range of variation, the mustelids exhibit some common characteristics. They are typically small animals with elongated bodies, short legs, short, round ears, and thick fur. Most mustelids are solitary, nocturnal animals, and are active year-round.
Most mustelid reproduction involves embryonic diapause. The embryo does not immediately implant in the uterus, but remains dormant for some time. No development takes place as long as the embryo remains unattached to the uterine lining. As a result, the normal gestation period is extended, sometimes up to a year. This allows the young to be born under more favorable environmental conditions. Reproduction has a large energy cost and it is to a female's benefit to have available food and mild weather. The young are more likely to survive if birth occurs after previous offspring have been weaned.
Mustelids are predominantly carnivorous, although some eat vegetable matter at times. While not all mustelids share an identical dentition, they all possess teeth adapted for eating flesh, including the presence of shearing carnassials. With variation between species, the most common dental formula is 22.214.171.124.
The martens, fisher and tayra are partially arboreal, while badgers are fossorial. A number of mustelids are have aquatic lifestyles, ranging from semiaquatic minks and the several species of river otters to the fully aquatic sea otter. The sea otter is one of the few nonprimate mammals known to use a tool while foraging. It uses "anvil" stones to crack open the shellfish that form a significant part of its diet. It is a "keystone species", keeping its prey populations in balance so some do not outcompete the others and destroy the kelp in which they live.
The black-footed ferret is entirely dependent on another keystone species, the prairie dog. A family of four ferrets eats 250 prairie dogs in a year; this requires a stable population of prairie dogs from an area of some 500 acres (2.0 km2).
The skunks were formerly included as a subfamily of the mustelids, but are now regarded as a separate family (Mephitidae). The mongoose and the meerkat bear a striking resemblance to many mustelids, but belong to a distinctly different suborder—the Feliformia (all those carnivores sharing more recent origins with the cats) and not the Caniformia (those sharing more recent origins with the dogs). Because the mongooses and the mustelids occupy similar ecological niches, convergent evolution has led to some similarity in form and behavior.
The oldest fossil of the mustelids were dated at the end of the Oligocene to the beginning of the Miocene. “There is debate regarding which fossils from these epochs represent possible ancestral forms that led to Mustelidae and which fossils represent the first modern mustelids.”(Wund, M. 2005. "Mustelidae" (On-line), Animal Diversity Web.) From the fossil record we can see that Mustelids appeared in the late Oligocene period (33 mya) in Eurasia and migrated throughout the continents. The Mustelids inhabit every continent except Antarctica and Australia. The mustelids migrated all throughout the continents that were connected during the early Miocene. The Mustelids made their way to North and South America via the Bering land bridge.
Several mustelids, including the mink, the sable (a type of marten) and the stoat (ermine), boast exquisite and valuable furs, and have been accordingly hunted since prehistoric times. Since the early Middle Ages, the trade in furs was of great economic importance for northern and eastern European nations with large native populations of fur-bearing mustelids, and was a major economic impetus behind Russian expansion into Siberia and French and English expansion in North America. In recent centuries, fur farming, notably of mink, has also become widespread and provides the majority of the fur brought to market.
One species, the sea mink (Neovison macrodon) of New England and Canada, was driven to extinction by fur trappers. Its appearance and habits are almost unknown today because no complete specimens can be found and no systematic contemporary studies were conducted.
The sea otter, which has the densest fur of any animal, narrowly escaped the fate of the sea mink. The discovery of large populations in the North Pacific was the major economic driving force behind Russian expansion into Kamchatka, the Aleutian Islands, and Alaska, as well as a cause for conflict with Japan and foreign hunters in the Kuril Islands. Together with widespread hunting in California and British Columbia, the species was brought to the brink of extinction until an international moratorium came into effect in 1911.
Today, some mustelids are threatened for other reasons. Sea otters are vulnerable to oil spills and the indirect effects of overfishing; the black-footed ferret, a relative of the European polecat, suffers from the loss of American prairie; and wolverine populations are slowly declining because of habitat destruction and persecution. The rare European mink Mustela lutreola is one of the most endangered mustelid species.
One mustelid, the ferret, has been domesticated and is a fairly common pet.
The 56 living mustelids are classified into eight subfamilies in 22 genera.
Fossil mustelids Extinct genera of the family Mustelidae include:
Multigene phylogenies constructed by Koepfli et al. (2008) and Law et al. (2018) found that Mustelidae comprises eight subfamilies. The early mustelids appear to have undergone two rapid bursts of diversification in Eurasia, with the resulting species only spreading to other continents later.
Mustelid species diversity is often attributed to an adaptive radiation coinciding with the Mid-Miocene Climate Transition. Contrary to expectations, Law et al. (2018) found no evidence for rapid bursts of lineage diversification at the origin of Mustelidae, and further analyses of lineage diversification rates using molecular and fossil-based methods did not find associations between rates of lineage diversification and Mid-Miocene Climate Transition as previously hypothesized.
Badgers are short-legged omnivores in the families Mustelidae (which also includes the otters, polecats, weasels, and wolverines), and Mephitidae (which also includes the skunks). They are not a natural taxonomic grouping, but are united by possession of a squat body adapted for fossorial activity. All belong to the caniform suborder of carnivoran mammals. The 11 species of mustelid badgers are grouped in four subfamilies: Melinae (4 species, including the European badger), Helictidinae (5 species of ferret-badger), Mellivorinae (the honey badger or ratel), and Taxideinae (the American badger); the respective genera are Arctonyx, Meles, Melogale, Mellivora and Taxidea. Badgers include the most basal mustelids; the American badger is the most basal of all, followed successively by the ratel and Melinae; the estimated split dates are about 17.8, 15.5 and 14.8 million years ago, respectively. The two species of Asiatic stink badgers of the genus Mydaus were formerly included within Melinae (and thus Mustelidae), but more recent genetic evidence indicates these are actually members of the skunk family.Badger mandibular condyles connect to long cavities in their skulls, which gives resistance to jaw dislocation and increases their bite grip strength. This in turn limits jaw movement to hinging open and shut, or sliding from side to side, but it does not hamper the twisting movement possible for the jaws of most mammals.
Badgers have rather short, wide bodies, with short legs for digging. They have elongated, weasel-like heads with small ears. Their tails vary in length depending on species; the stink badger has a very short tail, while the ferret badger's tail can be 46–51 cm (18–20 in) long, depending on age. They have black faces with distinctive white markings, grey bodies with a light-coloured stripe from head to tail, and dark legs with light-coloured underbellies. They grow to around 90 cm (35 in) in length including tail.
The European badger is one of the largest; the American badger, the hog badger, and the honey badger are generally a little smaller and lighter. Stink badgers are smaller still, and ferret badgers smallest of all. They weigh around 9–11 kg (20–24 lb), with some Eurasian badgers around 18 kg (40 lb).Burmese ferret-badger
The Burmese ferret-badger (Melogale personata), also known as the large-toothed ferret-badger, is a species of mammal in the family Mustelidae.Carnivora
Carnivora (; from Latin carō (stem carn-) "flesh" and vorāre "to devour") is a diverse scrotiferan order that includes over 280 species of placental mammals. Its members are formally referred to as carnivorans, whereas the word "carnivore" (often popularly applied to members of this group) can refer to any meat-eating organism. Carnivorans are the most diverse in size of any mammalian order, ranging from the least weasel (Mustela nivalis), at as little as 25 g (0.88 oz) and 11 cm (4.3 in), to the polar bear (Ursus maritimus), which can weigh up to 1,000 kg (2,200 lb), to the southern elephant seal (Mirounga leonina), whose adult males weigh up to 5,000 kg (11,000 lb) and measure up to 6.7 m (22 ft) in length.
Carnivorans have teeth and claws adapted for catching and eating other animals. Many hunt in packs and are social animals, giving them an advantage over larger prey. Some carnivorans, such as cats and pinnipeds, depend entirely on meat for their nutrition. Others, such as raccoons and bears, are more omnivorous, depending on the habitat. The giant panda is largely a herbivore, but also feeds on fish, eggs and insects. The polar bear subsists mainly on seals.
Carnivorans are split into two suborders: Feliformia ("catlike") and Caniformia ("doglike").Ferret-badger
Ferret-badgers are the five species of the genus Melogale, which is the only genus of the monotypic mustelid subfamily Helictidinae.
Bornean ferret-badger (Melogale everetti)
Chinese ferret-badger (Melogale moschata)
Javan ferret-badger (Melogale orientalis)
Burmese ferret-badger (Melogale personata)
Vietnam ferret-badger (Melogale cucphuongensis)Guloninae
Guloninae is a subfamily of the mammal family Mustelidae distributed across Eurasia and the Americas. It includes martens and the fisher, tayra and wolverine. These genera were formerly included within a paraphyletic definition of the mustelid subfamily Mustelinae.
Most gulonine species are arboreal to a degree. Some of the fashion furs come from this subfamily, i.e. sable, marten.Ictonychinae
Ictonychinae is a subfamily of the mammal family Mustelidae found mainly in the Neotropics (3 species) and Africa (3 species), with one Eurasian member. It includes the grisons, Patagonian weasel, striped polecats, African striped weasel and marbled polecat, respectively. These genera were formerly included within a paraphyletic definition of the mustelid subfamily Mustelinae.
Most members have a mask-like bar or larger dark marking across their face; the African representatives of the group are striped. A defense mechanism common to the group is use of a chemical spray similar to (but not necessarily as strong as) that of skunks.Ictonyx
Ictonyx is a genus in the family Mustelidae (weasels). It contains two species :
Saharan striped polecat (Ictonyx libycus)
Striped polecat (Ictonyx striatus)Marine otter
The marine otter (Lontra felina) is a rare and poorly known South American mammal of the weasel family (Mustelidae). The scientific name means "otter cat", and in Spanish, the marine otter is also often referred to as gato marino: "marine cat". The marine otter (while spending much of its time out of the water) only lives in saltwater, coastal environments and rarely ventures into freshwater or estuarine habitats. This saltwater exclusivity is unlike most other otter species, except for the almost fully aquatic sea otter (Enhydra lutris) of the north Pacific.Marten
The martens constitute the genus Martes within the subfamily Guloninae, in the family Mustelidae. Martens are slender, agile animals, adapted to living in taigas, and are found in coniferous and northern deciduous forests across the Northern Hemisphere. They have bushy tails and large paws with partially retractible claws. The fur varies from yellowish to dark brown, depending on the species, and, in many cases, is valued by fur trappers.Meles (genus)
Meles is a genus of badgers containing three living species, the Japanese badger (Meles anakuma), Asian badger (Meles leucurus), and European badger (Meles meles). In an older categorization, they were seen as a single species with three subspecies (Meles meles anakuma, Meles meles leucurus and Meles meles meles). There are also several extinct members of the genus. They are members of the subfamily Melinae of the weasel family, Mustelidae.Mesocarnivore
A mesocarnivore is an animal whose diet consists of 30–70% meat with the balance consisting of non-vertebrate foods which may include fungi, fruits, and other plant material. Mesocarnivores are seen today among the Canidae (coyotes, foxes), Viverridae (civets), Mustelidae (martens, tayra), Procyonidae (ringtail, raccoon), Mephitidae (skunks), and Herpestidae (some mongooses).Mink
Mink are dark-colored, semiaquatic, carnivorous mammals of the genera Neovison and Mustela, and part of the family Mustelidae which also includes weasels, otters and ferrets. There are two extant species referred to as "mink": the American mink and the European mink. The extinct sea mink is related to the American mink, but was much larger. The American mink is larger and more adaptable than the European mink but, due to variations in size, an individual mink usually cannot be determined as European or American with certainty without looking at the skeleton; however, all European mink have a large white patch on their upper lip, whereas only some American mink have this marking: therefore, any mink without the patch is certainly of the American species. Taxonomically, both American and European mink were placed in the same genus Mustela, but most recently, the American mink has been reclassified as belonging to its own genus Neovison.The American mink's fur has been highly prized for use in clothing, with hunting giving way to farming. Their treatment on fur farms has been a focus of animal rights and animal welfare activism. American mink have established populations in Europe (including Great Britain) and South America, after being released from mink farms by animal rights activists, or otherwise escaping from captivity. In the UK, under the Wildlife & Countryside Act 1981, it is illegal to release mink into the wild. In some countries, any live mink caught in traps must be humanely killed.American mink are believed by some to have contributed to the decline of the less hardy European mink through competition (though not through hybridization—native European mink are in fact more closely related to polecats than to North American mink). Trapping is used to control or eliminate introduced American mink populations.Mink oil is used in some medical products and cosmetics, as well as to treat, preserve and waterproof leather.Mustelinae
Mustelinae is a subfamily of family Mustelidae, which includes weasels, ferrets amd minks.It was formerly defined in a paraphyletic manner to also include wolverines, martens, and many other mustelids, to the exclusion of the otters (Lutrinae).Musteloidea
Musteloidea is a superfamily of carnivoran mammals united by shared characters of the skull and teeth. Musteloids share a common ancestor with the pinnipeds, the group which includes seals.The Musteloidea consists of the families Ailuridae (red pandas), Mustelidae (mustelids: weasels, otters,
martens, and badgers), Procyonidae (procyonids: raccoons, coatis, kinkajous, olingos, olinguitos, ringtails and cacomistles), and Mephitidae (skunks and stink badgers).
In North America, ursoids and musteloids first appear in the Chadronian (late Eocene). In Europe, ursoids and musteloids first appear in the early Oligocene immediately following the Grande Coupure.
The cladogram is based on molecular phylogeny of six genes in Flynn (2005), with the musteloids updated following the multigene analysis of Law et al (2018).Otter
Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the weasel family Mustelidae, which also includes badgers, honey badgers, martens, minks, polecats, and wolverines.Stink badger
Stink badgers (Mydaus) are a genus of the skunk family of carnivorans, the Mephitidae. They resemble the better know members of family Mustelidae also termed 'badgers' (which are themselves a polyphyletic group). There are only two extant species - the Palawan stink badger (M. marchei), and the Sunda stink badger or Teledu (M. javanensis). They live only on western islands of the Malay Archipelago: Sumatra, Java, Borneo and (in the case of the Palawan stink badger) on the Philippine island of Palawan; as well as many other, smaller islands in the region.
Stink badgers are named for their resemblance to other badgers and for the foul-smelling secretions that they expel from anal glands in self-defense (which is stronger in the Sunda species).Stink badgers were traditionally thought to be related to Eurasian badgers in the subfamily Melinae of the weasel family of carnivorans (the Mustelidae), but recent DNA analysis indicates they share a more recent common ancestor with skunks, so experts have now placed them in the skunk family (the Mephitidae, which is the sister group of a clade composed of Mustelidae and Procyonidae, with the red panda also assigned to one of the sister clades). The two existing species are different enough from each other for the Palawan stink badger to be sometimes classified in its own genus, Suillotaxus.Striped polecat
The striped polecat (Ictonyx striatus) - also called the African polecat, zoril, zorille, zorilla, Cape polecat, and African skunk - is a member of the family Mustelidae that resembles a skunk (of the family Mephitidae). The name "zorilla" comes from the word "zorro", which in Spanish means "fox". It lives predominantly in dry and arid climates, such as the savannahs and open country of Central, Southern, and sub-Saharan Africa, excluding the Congo basin and the more coastal areas of West Africa.Vietnam ferret-badger
The Vietnam ferret-badger (Melogale cucphuongensis) is a member of the family Mustelidae native to Vietnam. It was described in 2011 and is known from only two specimens.Weasel
A weasel is a mammal of the genus Mustela of the family Mustelidae. The genus Mustela includes the least weasels, polecats, stoats, ferrets and minks. Members of this genus are small, active predators, with long and slender bodies and short legs. The family Mustelidae (which also includes badgers, otters, and wolverines) is often referred to as the "weasel family". In the UK, the term "weasel" usually refers to the smallest species, the least weasel (M. nivalis).Weasels vary in length from 173 to 217 mm (6.8 to 8.5 in), females being smaller than the males, and usually have red or brown upper coats and white bellies; some populations of some species moult to a wholly white coat in winter. They have long, slender bodies, which enable them to follow their prey into burrows. Their tails may be from 34 to 52 mm (1.3 to 2.0 in) long.Weasels feed on small mammals and have from time to time been considered vermin because some species took poultry from farms or rabbits from commercial warrens. They do, on the other hand, eat large numbers of rodents. They can be found all across the world except for Antarctica, Australia, and neighbouring islands.
Extant Carnivora species