Wildlife Act 1976 / 2000
Bern Convention Appendix III
Key Identification Features
The Irish stoat has a reddish to brown coat with a white underbelly, they moult this coat twice a year, first in spring and then again in the autumn. The Irish population is considered a separate sub species as it is generally smaller, has darker fur and its white underbelly is less while defined compared to stoats in other European countries, also they do not moult white coats in the winter like more northerly stoat populations. Irish stoats have long thin cylindrical bodies supported by short legs. Males are larger than females with the average adult male measuring up to 40cm for the head and body while the females are shorter measuring up to 30cm. Stoats have long slender tails in proportion to their bodies which have a distinctive black tip at the end, males grow slightly longer tails than females which can measure up to 14cm in length. Adult males weigh up to 400 grams with females being much lighter weighing on average 200 grams. Unusually for mammals there is a noticeable difference in the size of the Irish population of stoats with individuals in the south being bigger and heavier than those found in more northern areas. They have flat pointed heads which contain small eyes and ears with a protruding snout giving them an almost rat like appearance. Stoats have excellent vision and largely hunt by sight, their senses of smell and hearing are also well developed. Track impressions of the hind feet show five clawed toes measuring up to 5cm in length. The stoat is a capable climber, can swim well if required and is able to run quite fast for short distances, the normal movement style of the stoat is a bounding stride interrupted by periods of standing upright on the hind legs to survey the area. They are not a particularly vocal species but mothers will emit a twittering call to their young while hissing and chattering sounds are used when threatened.
Irish stoats have adapted to a large number of different habitat types but prefer an area that provides some cover. They can be found in woodlands, hedgerows, marsh, heather, lowland farms, moorland, coastal areas and on small mountains. They have a particular preference for open woodlands and rocky scrub covered areas or if found on agricultural lands they will be located near any stone walls, ditches or hedgerows. The only areas that are unsuitable for a stoat’s habitat requirements are open land devoid of any cover and on higher mountains. Stoat dens can be created in a number of different locations including abandoned rabbit burrows, hollows in large trees, rock crevices and even in unused buildings. Dens are a warm, dry secure place where the stoat can rest or sleep and are usually lined with fur. Each stoat’s home range will vary in relation to the amount of food it can supply, for example a relatively poor area for prey numbers will see the stoat extend it’s territory to up to 100 hectares while another area rich in food sources will be much smaller averaging around 20 hectares. Each territory will have a number of different dens which will be visited regularly for rest and sleep as it may take a stoat several days to cover its entire range in search of food.
Food and Feeding Habits
Irish stoats are skilled hunters who are not fussy in what they eat. They generally prey on rodents, birds, rabbits and insects. Male stoats will stalk and kill prey much larger than itself while the females concentrate on smaller mammals like shrews, mice and rats. A single strong bite to the back of the neck is the favored method of attack for stoats. While they are largely carnivorous they will supplement their diets with berries and fruits depending on their seasonal availability. While above ground stoats use their eyesight to locate prey such as birds, reptiles and voles while they use their sense of smell if hunting rabbits or rats below ground. Stoats are good climbers so they will eat bird’s eggs from the nest and as they are competent swimmers they can hunt fish in slow moving rivers and along a lake’s shore. Stoats are not strictly nocturnal but the majority of their hunting is carried out at night while they are more likely to be seen during the day in the summer months. As they have high metabolisms and tend to lose heat due to their elongated body shape they must consume up to 20% of their own body weight each day in food. Hunting trips will be carried out regularly across their territories in between rest periods in one of their numerous dens.
Reproduction and Life Cycle
The main breeding season for the Irish stoat begins in May and ends in July. An unusual adaptation for small mammals sees a long delay period between mating and the time when gestation begins, this is done to ensure that the young are born the following year in early summer so as to avail of better conditions and food supply. Irish stoats produce one litter per year with each litter containing between five and twelve young known as kits. When born the kits are blind, deaf and have a light covering of fluffy white fur weighing only 4 grams. They are totally dependent on their mother and are fully weaned after five weeks. Rapid growth will see the young stoats becoming fully independent after twelve weeks by which time their mothers will have taught them several hunting techniques which they will need when establishing their own territories. Another unusual reproductive trait of the Irish stoat is that some female kits can become sexually mature after only a few weeks, if mating occurs with an adult male then the young stoat can become pregnant while still being weaned by her mother although the delayed gestation period of stoats means she will not give birth until the following year once she sets up her own territory. Stoats have been recorded to have lived for up to 10 years but the average life span in Ireland is 3 years.
Believed to have originated in central Europe the stoat is now the most widespread of the Mustelid family which includes species such as the weasel, ermine and mink. Stoats are now found throughout Europe, Asia and North America along northern latitudes while they are absent from the southern hemisphere. The Irish sub species of stoat is one of Ireland’s longest resident mammals and can be found throughout the country in any area that contains vegetation cover, except on some islands and mountainous regions. Population densities vary greatly according to the availability of food but generally any area which contains a sizable population of disease free rabbits will also have a high population of Irish stoats.
The Irish stoat is now a legally protected animal but was once considered a vermin species. The decline of the fur trade worldwide has also helped to protect stoat populations both in Ireland and elsewhere as their pelts were highly sought for clothes making. Some Irish stoat populations have diets that are composed of 50 % rabbit so they are linked to the success of their prey species. If an outbreak of the myxomatosis virus were to occur in the Irish rabbit population then the stoat population would be seriously effected. Being opportunistic feeders the Irish stoat can become a pest species in some areas due to their tendency to eat birds and their eggs. This can especially become a problem in reserves created to breed and hunt ground nesting game birds like grouse and pheasant, also stoats have been known to raid chicken houses on farms if hunting their normal prey species is unsuccessful. As they are now a legally protected species fencing is the most common defense used to deter hungry stoats.