Stoats
The Stoat is a mammal of the Mustelidae family which includes other carnivorous mammals such as the Weasel, Badger, Otter and Pine Marten. The name ermine is often but not always used for the Stoat in its pure white winter coat.
The Stoat is similar to the Weasel in general proportions, manner of posture and movement although the tail is relatively longer and has a prominent black tip, always exceeding a third of the body length. The dimensions of the Stoat are variable, but not as significantly as the Weasel's, and its size tends to decrease proportionally with latitude. Sexual dimorphism in size is pronounced with males being roughly 25% larger than females and 1.5 to 2 times their weight. On average, males measure 7.4 to 12.8 inches in body length whilst females measure 6.7 to 10.6 inches. The tail measures 3 to 4.7 inches in males and 2.6 to 4.2 inches in females. Males weigh around 9.1 ounces whilst females weigh less than 6.3 ounces.
The Stoat has an elongated neck with the head being set exceptionally far in front of the shoulders. The trunk is nearly cylindrical and it does not bulge at the abdomen. The greatest circumference of the body is little more than half its length. The eyes are round, black and protrude slightly. The whiskers are brown or white in colour and very long. The ears are short, rounded and lie almost flattened against the skull. The claws are not retractable and are large in proportion to the digits. Each foot has 5 toes.
The Stoat’s winter fur is very dense and silky but quite short whilst the summer fur is rougher, shorter and sparse. In summer, the fur is sandy-brown on the back and head and white below. In the Stoat's northern range, it adopts a completely white coat (save for the black tail tip) during the winter period. Differences in the winter and summer coats are less apparent in southern forms. In the southern range, the coat remains brown but is denser and sometimes paler than in summer.
The Stoat can be found throughout north America, Europe and Asia from Greenland and the Canadian and Siberian Arctic islands south to about 35°N. In Europe it is found as far south as 41ºN in Portugal and inhabits most islands with the exception of Iceland, Svalbard, the Mediterranean islands and some small North Atlantic islands. In north America it is found throughout Alaska and Canada south through most of the north USA to central California, north Arizona, north New Mexico, Iowa, the Great Lakes region, New England and Pennsylvania but it is absent from most of the Great Plains and south east USA. In the late 19th century, the Stoat was introduced to New Zealand to control rabbits where it has had a devastating effect on native bird populations.
Mating occurs in April to July. The Stoat is not monogamous and litters are often of mixed paternity. The gestation period lasts around 280 days. Males play no part in rearing the young which are born blind, deaf, toothless and covered in fine white or pinkish down. The milk teeth erupt after 3 weeks and solid food is eaten after 4 weeks. The eyes open after 5 to 6 weeks with the black tail tip appearing a week later. Lactation ends after 12 weeks.
The territories of male Stoats encompass smaller female territories which they defend from other males. The size of the territory and the ranging behaviour varies seasonally and depends on the abundance of food and mates. During the breeding season, the ranges of females remain unchanged whilst males either become roamers, strayers or transients. Dominant older males can have territories 50 times larger than those of younger, socially inferior males. Both sexes mark their territories with urine, faeces and scent marks.
Males and females typically live apart but close to each other. Each Stoat has several dens dispersed within its range. A single den has several galleries, mainly within 12 inches of the surface. The Stoat does not dig its own den but instead uses the burrows and nest chambers of the rodents it kills. The skins and underfur of rodent prey are used to line the den. The den is sometimes located in seemingly unsuitable places such as among logs piled against the walls of houses. The Stoat also inhabits old and rotting stumps, tree roots, heaps of brushwood, haystacks, bog hummocks, cracks of vacant buildings, rock piles and rock clefts.
As with the Weasel, rodents predominate in the Stoat's diet. However, unlike the Weasel, which almost exclusively feeds on small voles, the Stoat regularly preys on larger rodent and rabbit and hare species and it will kill prey far larger than itself. It is an opportunistic predator and moves rapidly checking every available burrow or crevice for food. Because of its larger size, the male is less successful than the female in pursuing rodents far into tunnels. The Stoat will regularly climb trees to gain access to birds' nests and it is a common raider of nest boxes. The Stoat seeks to immobilize large prey such with a bite to the spine at the back of the neck. Small prey typically dies instantly from a bite to the back of the neck whilst larger prey typically dies of shock since the Stoat's canine teeth are too short to reach the spinal column or major arteries.
Date: 20th June 2017
Location: Glen Quaich, Perthshire
The Stoat is similar to the Weasel in general proportions, manner of posture and movement although the tail is relatively longer and has a prominent black tip, always exceeding a third of the body length. The dimensions of the Stoat are variable, but not as significantly as the Weasel's, and its size tends to decrease proportionally with latitude. Sexual dimorphism in size is pronounced with males being roughly 25% larger than females and 1.5 to 2 times their weight. On average, males measure 7.4 to 12.8 inches in body length whilst females measure 6.7 to 10.6 inches. The tail measures 3 to 4.7 inches in males and 2.6 to 4.2 inches in females. Males weigh around 9.1 ounces whilst females weigh less than 6.3 ounces.
The Stoat has an elongated neck with the head being set exceptionally far in front of the shoulders. The trunk is nearly cylindrical and it does not bulge at the abdomen. The greatest circumference of the body is little more than half its length. The eyes are round, black and protrude slightly. The whiskers are brown or white in colour and very long. The ears are short, rounded and lie almost flattened against the skull. The claws are not retractable and are large in proportion to the digits. Each foot has 5 toes.
The Stoat’s winter fur is very dense and silky but quite short whilst the summer fur is rougher, shorter and sparse. In summer, the fur is sandy-brown on the back and head and white below. In the Stoat's northern range, it adopts a completely white coat (save for the black tail tip) during the winter period. Differences in the winter and summer coats are less apparent in southern forms. In the southern range, the coat remains brown but is denser and sometimes paler than in summer.
The Stoat can be found throughout north America, Europe and Asia from Greenland and the Canadian and Siberian Arctic islands south to about 35°N. In Europe it is found as far south as 41ºN in Portugal and inhabits most islands with the exception of Iceland, Svalbard, the Mediterranean islands and some small North Atlantic islands. In north America it is found throughout Alaska and Canada south through most of the north USA to central California, north Arizona, north New Mexico, Iowa, the Great Lakes region, New England and Pennsylvania but it is absent from most of the Great Plains and south east USA. In the late 19th century, the Stoat was introduced to New Zealand to control rabbits where it has had a devastating effect on native bird populations.
Mating occurs in April to July. The Stoat is not monogamous and litters are often of mixed paternity. The gestation period lasts around 280 days. Males play no part in rearing the young which are born blind, deaf, toothless and covered in fine white or pinkish down. The milk teeth erupt after 3 weeks and solid food is eaten after 4 weeks. The eyes open after 5 to 6 weeks with the black tail tip appearing a week later. Lactation ends after 12 weeks.
The territories of male Stoats encompass smaller female territories which they defend from other males. The size of the territory and the ranging behaviour varies seasonally and depends on the abundance of food and mates. During the breeding season, the ranges of females remain unchanged whilst males either become roamers, strayers or transients. Dominant older males can have territories 50 times larger than those of younger, socially inferior males. Both sexes mark their territories with urine, faeces and scent marks.
Males and females typically live apart but close to each other. Each Stoat has several dens dispersed within its range. A single den has several galleries, mainly within 12 inches of the surface. The Stoat does not dig its own den but instead uses the burrows and nest chambers of the rodents it kills. The skins and underfur of rodent prey are used to line the den. The den is sometimes located in seemingly unsuitable places such as among logs piled against the walls of houses. The Stoat also inhabits old and rotting stumps, tree roots, heaps of brushwood, haystacks, bog hummocks, cracks of vacant buildings, rock piles and rock clefts.
As with the Weasel, rodents predominate in the Stoat's diet. However, unlike the Weasel, which almost exclusively feeds on small voles, the Stoat regularly preys on larger rodent and rabbit and hare species and it will kill prey far larger than itself. It is an opportunistic predator and moves rapidly checking every available burrow or crevice for food. Because of its larger size, the male is less successful than the female in pursuing rodents far into tunnels. The Stoat will regularly climb trees to gain access to birds' nests and it is a common raider of nest boxes. The Stoat seeks to immobilize large prey such with a bite to the spine at the back of the neck. Small prey typically dies instantly from a bite to the back of the neck whilst larger prey typically dies of shock since the Stoat's canine teeth are too short to reach the spinal column or major arteries.
Date: 20th June 2017
Location: Glen Quaich, Perthshire
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Also in: Other mammals
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