Long-tailed weasels are endangered

Long-tailed weasel

The Long-tailed weasel (Mustela frenata) counts within the marten family (Mustelidae) to the genus of the weasel (Mustela). In English this will be a marten Long-tailed Weasel called.

Evolution, fossil finds

The earliest fossil finds of the long-tailed weasel come from Kansas, USA, and were dated to the early Pleistocene. Other finds come from the late Pleistocene and the Holocene. Most of them come from California, Colorado, Florida, Georgia, Idaho, New Mexico, Ohio, Texas, Tennessee and Wyoming. From the already extinct subspecies Mustela frenata gracilis fossils have been found in Arkansas. The immediate ancestor of the long-tailed weasel was likely Mustela rexroadensis (Hibbard, 1950). Mustela rexroadensis lived from the early to the late Pleistocene and probably died out around 20,000 years ago. <1>


Appearance and dimensions

The long-tailed weasel reaches a body length of 28 to 42 centimeters and a tail length of 12 to 30 centimeters, depending on gender. Males weigh between 160 and 450 grams, females between 80 and 250 grams, so females stay significantly smaller and lighter than males. Dorsally, the very soft fur has a strong brownish to cinnamon brown color. Ventrally, the fur is significantly lighter, mostly cream-colored to yellowish-brown in color. There are two changes of coat in one season. In spring, winter fur is replaced by summer fur within 20 to 35 days. In autumn, the summer fur is replaced by the very dense winter fur within 40 to 70 days. The bushy tail ends in a black colored tip. When moving, the tail is held at an angle of approximately 45 degrees to the ground. Northern subspecies wear whitish fur in winter, which is used to camouflage themselves in the snow. The fur consists of a dense undercoat, which protects against cold and wet, and of coarser outer hair lying on top. The head is extremely narrow and is only slightly separated from the neck. The small, rounded ears sit far back on the head. In the area of ​​the snout there are long whiskers, the so-called vibrissae, which serve for orientation. The slim body is carried by short but strong extremities. The toes of the feet end in small claws. Females have five pairs of teats to suckle their offspring. The dentition has 34 teeth, the dental formula is 3/3, 1/1, 3/3, 1/2. <2>

Way of life

Long-tailed weasels live solitary. The sexes meet only briefly during the mating season. Shortly after mating, however, a couple separates again. The rearing of the offspring is the sole responsibility of the female. Long-tailed weasels are extremely territorial. The territories of the males usually coincide with those of the females. However, territorial overlaps of the same sexes do not occur. The animals are active both during the day and at night. The long-tailed weasels use their highly developed sense of smell and hearing when locating prey. But the sense of sight is also quite well developed. A prey animal is killed by a bite in the neck or throat. Despite their short legs, long-tailed weasels are good and fast runners. Their climbing and swimming properties are also well developed. In winter, long-tailed weasels create tunnels under the snow cover. They hunt their prey on the ground, in trees and bushes, and also in the water. Communication with one another takes place via smell and a variety of sounds. The sounds are in the frequency range between 200 and 500 and between 750 and 1,000 Hz. <3> During the rest phases, long-tailed weasels rest in earth structures, in natural caves under stones or in rocks or in similarly protected places. The inside of a cave is padded with soft grass. In such a cave, the female gives birth to her offspring.


Long-tailed weasels occur in large parts of North and Central America. Some subspecies also live in northwestern South America. The distribution area in North America extends from southern Canada over large parts of the USA to Mexico. In Canada, the long-tailed weasel is mainly in British Columbia, Saskatchewan, Alberta and the southern parts of the provinces of Manitoba, Ontario and Québec. The USA and Mexico are largely populated except for deserts such as the Mojave and Sonora. In Central America, long-tailed weasels are particularly widespread in Guatemala, Honduras, Nicaragua, Costa Rica and Panama. <4> Light forests and their edges as well as rivers and other bodies of water are among the natural habitats. Long-tailed weasels occur in temperate as well as subtropical and tropical climatic regions. Dense forests and pure desert regions, on the other hand, are not populated.


Long-tailed weasels are on the menu of many predatory animals despite their ability to defend themselves. Below the mammals (Mammalia) mainly target red foxes (Vulpes vulpes), Coyotes (Canis latrans), Gray foxes (Urocyon cinereoargenteus), Spruce marten (Martes americana) and bobcats (Lynx rufus) after the life of the long-tailed weasel. Larger Owls (Strigiformes) like great horned owl (Bubo virginianus), Snow owls (Bubo scandiacus) and barred owl (Strix varia) and birds of prey (Falconiformes) like buzzards (Buteo lagopus) and hawk (Accipiter gentilis) target long-tailed weasels. The animals are less likely to fall prey to snakes. In these cases it is mostly Snakes (Serpentes) like rattlesnakes (Crotalidae), Water moccasin otters (Agkistrodon piscivorus) or the Massassauga (Sistrurus catenatus). Despite their relatively small size, long-tailed weasels are considered defensive animals. They defend themselves against much larger enemies with bites and blows from their paws. Nevertheless, many young animals in particular fall victim to the numerous carnivores. <5>


Long-tailed weasels are pure carnivores. They prefer to hunt prey up to rabbit size at night. Their preferred foods include house mice (Mus musculus), Grasshopper mice (Onychomys), American harvest mice (Reithrodontomys), Field mice (Microtus), Meadow jumping mice (Zapus hudsonius), White footed mice (Peromyscus), Voles (Arvicolinae), Cotton rats (Sigmodon), American bush rats (Neotoma), Lemming mice (Synaptomys), Muskrats (Ondatra zibethicus), Florida water rats (Neofiber), Lowland pocket rats (Geomys), Mountain Pocket Rats (Thomomys bottae) and similar animals. But also Ziesel (Spermophilus), Chipmunks (Tamias), North American red squirrels (Tamiasciurus), Gray squirrel (Sciurus carolinensis), Aberthörnchen (Sciurus aberti), Eastern Fox Squirrel (Sciurus niger), Assapane (Glaucomys volans), Northern flying squirrels (Glaucomys sabrinus), Snowshoe hares (Lepus americanus), Florida Cottontail (Sylvilagus floridanus) and Audubon cottontail rabbit (Sylvilagus audubonii) are captured quite often. In times of food shortage, they are not picky and go hunting Birds (Aves), their eggs, amphibians (Amphibia), Reptiles (Reptilia) and even insects (Insecta). Tree wedges (Spizella arborea), Virginia Quail (Colinus virginianus), Gold woodpeckers (Colaptes auratus), Singing chambers (Melospiza melodia), Junkos (Junco hyemalis), Blue-winged ducks (Anas discors) on the menu. <6> In severe winters it happens that they hunt for small animals only under the blanket of snow. To do this, they dig real tunnels under the blanket of snow. The hunt with the associated energy consumption makes it necessary to eat every day. The long-tailed weasel creeps up on a victim. Then he strikes at lightning speed and kills the victim with a bite in the neck or a bite in the neck. When searching for prey, the long-tailed weasel mainly relies on its well-developed sense of smell. But hearing and sight also play a major role in hunting. In late summer and autumn, berries and fruits are also eaten to a small extent.


The long-tailed weasel reaches sexual maturity at six to twelve months. In the temperate regions of North America, the mating season extends through late summer. The sexes live solitary. They only meet for a short time during the mating season and separate again shortly afterwards. The mating behavior can be described as polygamous, as a male usually mates with several females. With the long-tailed weasels, a delayed pregnancy comes into play, i.e. a so-called dormancy, in which the development of the egg cells temporarily stops. Embryonic or fetal development does not begin until early spring of the following year. It is assumed that the female organism reacts to the longer days and initiates the final phase of pregnancy. Depending on the mating season, the entire gestation period extends over 205 to 337 days. The pure embryonic development takes about 30 days. <7> A female gives birth to between four and five, rarely up to six, young animals in her nest. They are usually born in late April or May. The young are born within a few minutes. Usually there are barely six minutes between the first and last young animal. The young animals are initially still naked and blind and weigh only around three grams, they open their eyes in the fourth or fifth week of life. At the end of the second week of life they have grown their first coat. In the sixth week of life, breast milk is weaned and the young eat their first solid food. From this point on, they go hunting with their mother and learn the hunting techniques. The boys usually achieve independence at two months. Most young animals do not survive the first year of life due to the numerous carnivores.

Ecology, hazard and protection

Long-tailed weasels control the populations of rodents in their habitat through their healthy appetite (Rodentia) and thus keep the ecological balance in a position. Long-tailed weasels themselves, however, also form the food source for a number of carnivores. Thus, the long-tailed weasel is an important part of the complex ecosystem. Long-tailed weasels are not welcomed in the vicinity of humans, as they often feast on the farmers' poultry. On the other hand, on the farms and farms, they keep populations of mice (Mus) and similar animals small. Therefore, long-tailed weasels are mostly tolerated by farmers. In some regions, long-tailed weasels are hunted for their fur. However, the fur is nowhere near as important in economic terms as the fur of an American mink (Mustela vison). Long-tailed weasels are not considered endangered today. Therefore, the species is listed as not endangered on the IUCN Red List.



  • Mustela frenata frenata - Lichtenstein, 1831 - Texas, Eastern Mexico
  • Mustela frenata leucoparia - Merriam, 1896 - Mexico
  • Mustela frenata perotae - Hall, 1936 - Mexico
  • Mustela frenata macrophonius - Elliot, 1905 - Mexico
  • Mustela frenata goldmani - Merriam, 1896 - Mexico
  • Mustela frenata tropicalis - Merriam, 1896 - Mexico
  • Mustela frenata perda - Merriam, 1902 - southern Mexico - Guatemala
  • Mustela frenata nicaraguae - J. A. Allen, 1916 - Honduras, Nicaragua
  • Mustela frenata costaricensis - Goldman, 1884 - Costa Rica
  • Mustela frenata panamensis - Hall, 1932 - Panama
  • Mustela frenata texensis - Hall, 1936 - Texas
  • Mustela frenata neomexicana - Barber & Cockerell, 1898 - northern Mexico, southeastern Arizona, New Mexico, western Texas, southeastern Colorado, southwestern Kansas
  • Mustela frenata arizonensis - Mearns, 1891 - western New Mexico, Arizona
  • Mustela frenata inyoensis - Hall, 1936 - California
  • Mustela frenata pulchra - Hall, 1936 - California
  • Mustela frenata latirostra - Hall, 1936 - California
  • Mustela frenata nigriauris - Hall, 1936 - California
  • Mustela frenata xanthogenys - Gray, 1843-California
  • Mustela frenata munda - Bangs, 1899 - California
  • Mustela frenata oregonensis - Merriam, 1896 - California, Oregon
  • Mustela frenata saturatus - Merriam, 1896 - southern Oregon, northwest California
  • Mustela frenata altifrontalis - Hall, 1936 - Oregon, Washington, southwestern British Columbia
  • Mustela frenata washingtoni - Merriam, 1896 - Washington
  • Mustela frenata effera - Hall, 1936 - eastern Oregon, southeast Washington
  • Mustela frenata nevadensis - Hall, 1936 - southern British Columbia, Washington, Idaho, Utah, Nevada, northeast Arizona, northern New Mexico
  • Mustela frenata oribasus - Bangs, 1899 - British Columbia, Alberta, Montana, northern Wyoming
  • Mustela frenata longicauda - Bonaparte, 1838 - Alberta, Saskatchewan, southern Manitoba - eastern Montana, Dakota, Nebraska, southeastern Wyoming, northeastern Colorado, western Kansas
  • Mustela frenata alleni - Merriam, 1896 - southern Dakota (Black Hills), Wyoming, Nebraska
  • Mustela frenata spadix - Bangs, 1896 - Minnesota, Iowa, southeastern North Dakoa, eastern South Dakota, northeastern Nebraska
  • Mustela frenata noveboracensis - Emmons, 1840 - Ontario, Quebec - eastern United States (Carolina, northern Georgia, Alabama, Mississippi)
  • Mustela frenata occisor - Bangs, 1899-Maine
  • Mustela frenata primulina - Jackson, 1913 - Missouri, Arkansas, Iowa, eastern Kansas, Oklahoma, northern Louisiana, northeast Texas
  • Mustela frenata arthuri - Hall, 1927 - southeast Texas, Louisiana, Mississippi
  • Mustela frenata olivacea - Howell, 1913 - eastern Mississippi, Alabama, northern Georgia, South Carolina, northern Florida
  • Mustela frenata peninsulae - Rhoads, 1894 - Florida
  • Mustela frenata meridana - Hollister, 1914 - Venezuela

Literature and sources

Qualified web links

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