Mountain hare

Latin name

Lepus timidus

Class

Mammals

Group

Rabbits & Hares

The Mountain hare at a glance

First described from Uppsala in Sweden by Carl von Linné (aka Linnaeus) in 1758, mtDNA and nDNA evidence suggests that Lepus timidus, L. arcticus, and L. othus may have started diverging from a common ancestor around 270,000 years ago during the Middle Paleolithic. Multiple subspecies have been described, with several authors proposing 15 or 16, but the validity of most of these is dubious and, in their 2022 chapter on the species to the Handbook of the Mammals of Europe, Anders Angerbjörn and Stéphanie Schai-Braun suggest three can be treated as subspecies, given their geographical separation and distinct morphological characteristics: those in Ireland (L. t. hibernicus), Scotland/England (L. t. scoticus), and in the Alps (L. t. varronis). The species' binomial name is derived from the Latin for hare (Lepus) and timeo, Latin for timid or fearful, such that it's scientific name essentially translates as "fearful hare".

Size & Appearance: Range in head-body length from 46-61 cm (18-24 in.) with a 4-8cm (1.5-3 in.) tail. The hind feet are longer than the forelegs, growing to 12-17 cm (5-7 in.) - both paws are completely furred. The ears are large relative to the head, but proportionally smaller than those of brown hare, reaching 6-10 cm (2.4-4 in.) in length. Adult animals range in weight between 2 and 5 kg (4.4-11 lbs.), typically at the lower end between 2.5 and 3.5 kg (5.5-8 lbs); females are about 10-15% heavier than males. On average, the Scandinavian subspecies is the largest, then the Irish, with Scottish/English subspecies the smallest, although there is some overlap. The coat is very variable, but is broadly a dusky brown (sometimes approaching black) with pale/white underside during summer and white, silver/grey-white, or part-white (e.g., retaining a brown face, and/or dark ears, and/or dark back) in winter; the dusky blue underfur shows through on the flanks, giving the species its alternate name of "blue hare". Almost any transition of the summer and winter coat is possible and sometimes animal present with a brown body and white legs. The short tail (up to about 6 cm / 3 in.) is generally white in both coat phases and lacks the black markings of the brown hare. The black tips to the ears also persist through moults. The species moults twice per year: once between October and December into a white winter coat, and again between February and May into a grey-brown summer pelage. The moult is temperature dependent and triggered by changes in day length, with females entering it ahead of males.

Distribution: Globally distributed in tundra and boreal habitats from northern Europe, through Russia and Siberia, to Japan in the east, including throughout Norway, Finland, and Sweden, including Öland, Gotland, and Åland (i.e., the Baltic islands). In the UK and Ireland it's widespread throughout Ireland, which is appears confined mostly to the uplands of mainland Scotland (predominantly the Highlands). The species has been introduced to multiple islands, including Shetland, Hoy, Lewis, Harris, Skye, Raasay, Scalpay, Jura, and the Isle of Man. Despite becoming extinct in England around 6,000 BP, as the ice retreated and forests spread during the Mesolithic, Victorian enthusiasts translocated the species quite widely from Scotland into northern England and Wales during the late 19th century to provide sporting opportunities on English and Welsh grouse moors, including to Snowdonia, the Brecons, the Lake District and the Cheviots, although these seem to have survived only until the late 1970s. Today, one small English population persists in the Peak District, Derbyshire, having been introduced during the 1870s.

Habitat: Primarily an animal of open habitat such as woodland clearings, swamps/bogs/mires, river valleys, tundra, and heather moorlands at all altitudes, although highest densities in Scotland appear to persist between 300 and 900 m (1,000-3,000 ft). In Ireland hares may occupy lowland agricultural areas, meadowland, and grassland, with rushes and hedgerows apparently important daytime resting areas. Broadly speaking, the species is attracted to diverse habitats with a lots of vegetation layers, an abundance of saplings, and storeyed vegetation structures. They will use non-conifer forestry plantations, particularly during inclement weather.

Longevity/Mortality: The heaviest mortality appears to be during the first year (~80%), as with most mammals, particularly in late summer and autumn, declining to about 60% mortality among adults. The average survival seems to be 3 or 4 years old, although there are records of 5 or 6 years old in the wild and possibly up to 9 years old. The oldest on record was female kept in captivity in Tokyo that reached 11 years. Long-term monitoring data are limited, but a seven-decade-long study by Adam Watson and Jeremy Wilson, published in 2018, suggested long-term declines on both moorland and grouse moor sites in eastern Scotland, with the latter experiencing the highest rate of decline post-1999. Many adult hares are killed in driven shoots by gamekeepers between January and May aimed at reducing densities below 5 per sq-km to protect grouse from the Orthoflavivirus loupingi flavivirus (colloquially known as louping-ill) transmitted by Ixodes ricinus ticks, for which hares are a host. Longer term trends in decline are associated with land use changes and, overall, human impact is probably now the most significant source of mortality for Mountain hares. In some parts of their range, the species undergoes "boom and bust" cycles, with the population crashing between every 3 and 12 years through parasitism, predation, and/or starvation.

Predators: Hares have a wide variety of predators. Here in Britain, hares are taken by (or are potential prey for) foxes, wildcats, stoats, pine martens, goshawks, golden eagles, white-tailed eagles, hen harriers, common and rough-legged buzzards, peregrine falcons, and long-eared and eagle owls. Across their range, mink, raccoon dogs, wolves, lynx, wolverines, Arctic foxes, snowy owls, gyr falcons, and ural owls will also take Mountain hares. Studies from the Fennoscandian Peninsula imply foxes are probably the only predator able to impact at the population scale, although this is unlikely to be the case in Scotland. Some hares, particularly leverets, are killed by domestic dogs and cats.

Sexing: Very difficult, if not impossible, to sex at distance. The testes are descended between December and May, and males tend to present with a broader and squarer head, which may help separating sexes at close range. In the hand, sex can be determined by the circular genital aperture of males.

Activity: Activity patterns are highly seasonal and the species is broadly nocturnal, with the peak of activity around dawn and dusk, and it is overnight when the majority of feeding appears to occur. During the day hares are often found resting in shallow scrapes in the ground called a form, ears flat against their back and eyes half closed. One 1986 study in the Highlands found that more than 90% of day forms were in old heather, the animals moving to short young heather, wild grasses, or high pastures to feed. Increasing daytime activity is observed during the short summer nights and in the winter where food is scarce and, overall, most daylight activity is observed between April and June. Boxing, where two hares sit on their hind legs and jab at one another with their forefeet, in particular may be seen during day in spring.

Territory/Range: A non-territorial species, with considerable overlap in ranges within and between sexes, although a dominance hierarchy among males may result localised displacement of some individuals during periods of food shortage caused by extensive snow. Ranges are highly variable with sex, season, and habitat, although males consistently range over larger areas than females, moving furthest during the breeding season, while breeding females move the least. Males are known to range over around 110 ha (270 acres) in mixed upland habitat, while females in the same habitat utilise only 85-90 ha (220 acres). In high quality habitats (e.g., improved pasture) the range of both sexes may reduce 10 ha (25 acres) or less. Daily travel for males estimated to be 1 to 3 km (0.5-2 miles), covering maybe 15 ha (37 acres). Elsewhere in Europe ranges of up to 300 ha (740 acres) have been recorded, and ranges are likely much larger in northern Russia and Siberia but data are lacking.

Diet & Feeding: A herbivorous species that takes the bark, leaves and twigs of most deciduous trees and shrubs, including willow, birch, mountain ash, poplar, hazel, and juniper. In Scotland and Ireland, heather appears to dominate the diet (up to 90% of food taken during winter), while graminoids (grasses/sedges/rushes) constitute the majority elsewhere. Gorse, legumes and occasionally other crops are also taken where hares inhabit agricultural land, as well as clover. There's some evidence of a shift away from heather to graminoids by lactating females, presumably because the high phenol content of Calluna and Betula reduces digestive efficiency, causing them to lose sodium. In common with other lagomorphs, this species produces two types of faecal pellet: a soft/unformed mucosal pellet called a cecotrope that is eaten directly from anus in a behaviour known as refection, and a smaller dry, hard pellet (faecal pellet) that's not re-eaten. Refection increases of the soft pellets occurs during the day and increases the digestibility by up to 25%.

Reproduction: The breeding season runs from January until June, and potentially outside of this given that pregnant females have been recovered in January and August. Courtship involves several males pursuing a female, sometimes for hours, with females rearing up and "boxing" at over-amorous males to rebuke their advances. Males will also fight amongst themselves for access to females. A litter of typically 1 to 4 young (called leverets) is born after a gestation that averages 50 days, based on captive animals. The number of litters per year and litter size varies with location and the age and condition (i.e., body weight) of the mother - litter size may be up to 8 leverets, and in productive southern habitats females may produce 3 or 4 litters per year. The female will often mate shortly (i.e., a few hours) after parturition, promoting multiple litters, with late and early conception resulting in young born between January and October. Superfetation, where a female carries embryos of two different development stages, occurs, although appears less common than in Brown hares. Young are born fully furred with their eyes open and will commence suckling immediately, continuing to for 2 to 6 weeks. Weight at birth varies significantly with mother's condition and litter size, ranging from around 60 to 180 g (2-6 oz.). Leverets are left alone for first week after birth while mother feeds -- she'll return around dusk to suckle -- and the rich milk permits rapid growth, leverets putting on 14 to 30 g (0.5-1 oz.) per day, albeit that early litters appear to grow more slowly. Young are fully grown by around 4 months and sexually mature in their second year. There are some records from Sweden of sterile Brown-Mountain hybrids, female Mountain hares mating with male Brown hares, but cross-breeding appears rare.

Behaviour & Sociality: Can be found solitarily, but will often move, rest, and feed in small groups of 2 to 5 individuals, although groups up to 100 were counted at Aldergrove Airport, Belfast up to late 1960s. Females appear dominant to males in all seasons. Mountain hares have a well-developed sense of smell, scent marking vegetation and rocks with urine and scent from inguinal glands, which are most active during the breeding season. Hares swim well and run in a wide arc when disturbed, rather than the zig-zagging of the Brown hare, reaching a top speed of about 64 kmh (40 mph). Typically rests by day among rocks and rock crevices, sometimes in an unlined form it has dug itself. If undisturbed, the same form may be used for several weeks (the form persisting up to 25 years in one Scottish study, presumably used by generations of hares), or changing according to the weather. In parts of their northern range they may dig burrows that are used by leverets and in Russia complex burrows extending several metres have been recorded. Vocalisation is rare, but they will scream when injured or fearful, and whistle or hiss when startled or aggressive (e.g., while defending resources).

Threats: Widely persecuted for damage to forestry, and occasionally crops, as well as by game keepers both for eating heather intended for gamebirds and as possible route for transmission of louping ill (encephalomyelitis) to grouse. Mountain hares are listed on Annexe V of EC 1992 Habitats Directive (EC 92/43EEC), which restricts methods of capture but offers no significant protection in Britain. More protection is afforded in Ireland under the Irish Wildlife Act (1976) and Northern Ireland under the Special Protection Order (2004). The Hunting Act (2004) prohibits coursing (chasing with dogs) in England and Wales, although this remains a popular pursuit in some areas. The UK population has been estimated at between 526,000 and 81,000; likely around 135,000. The recent (2018) Mammal Red List produced by The Mammal Society lists the species as Vulnerable in England and Near Threatened in Scotland, while the IUCN considers it of Least Concern globally.

Mountain hare in detail

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Bibliography

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