Short-tailed field vole

The short-tailed field vole is a small, dark brown rodent with a short tail, distinguishable from the closely related common vole (Microtus arvalis) by its darker, longer and shaggier hair and by its more densely haired ears. The head and body length varies between and the tail between . The weight is . The voice is a faint, low squeak and it also emits a range of chattering sounds. ==Distribution and habitat==

The short-tailed field vole has a palearctic distribution. Its range extends throughout Western Europe and eastwards to Lake Baikal in Siberia and north west China and northward to Norway, Sweden and Finland. It is absent from Iceland and thins out southwards towards the Mediterranean Sea. Previously absent, it was detected in Ireland in 2022. It is found in a range of habitats including meadows, field borders, plantations, woodland verges, clearings, upland heaths, dunes, marshes, bogs and river banks and tends to prefer wet areas. It is found at altitudes of up to about . ==Behaviour==

The short-tailed field vole is more active by day than the common vole. It excavates shallow burrows close to the surface of the ground, under leaf litter and under snow in winter. It also makes surface runs through tall vegetation, routes along which it can scurry back to safety if danger threatens. Off these are dedicated defecation sites and it often leaves little piles of chopped up grass stalks nearby. Field voles are an important part of the diet of barn owls and they are also preyed on by kestrels, other owls, weasels, stoats, foxes and snakes. Though very numerous, they have little impact on man except in plague years when they may cause significant damage to crops. ==Breeding==

Field voles are induced ovulators. The short-tailed field vole breeds throughout the year but the breeding season peaks in spring and summer. The nest is made on or just under the surface of the ground, often in a clump of grass or sedge. The gestation period is about three weeks and up to a dozen young are borne. These grow rapidly, suckle for twelve days and leave the nest at twenty one days, reaching sexual maturity soon afterwards. Like the common vole, the short-tailed field vole is subject to population explosions when conditions are right. Male field voles maintain a territory but females just have a home range which may overlap with that of a neighbour. After leaving the nest, young female voles remain in or near their mother's home range but young males are forced to disperse by the aggressiveness of the adult males. Female field voles sometimes spontaneously move in the time gap between weaning one litter and producing the next, a phenomenon typical of this species. One of the causes of the large population swings that occur in the short-tailed field vole is the scramble competition which comes into play when the most desirable food plants are less available in mid summer. ==Conservation status==

The short-tailed field vole is common over most of its very wide range, although thinning out towards the peripheries and may be locally scarce where conditions are less suitable. The population seems stable over the long term though there are marked fluctuations from year to year. The IUCN in its Red List of Threatened Species has therefore listed it as being of "Least Concern". ==References==