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The flexible mountain Glenn Iason and Scott Newey consider the , and how it might respond to woodland expansion and environmental changes here in .

he mountain hare (Lepus (Calluna vulgaris) moorlands of that allow them to neutralise natural timidus), also known as the north-east Scotland [3]. Management chemical defences of woody plants. variable hare, certainly lives of these areas by predator control Tup to its name. It changes colour and muirburn (prescribed burning of Mountain have special into varying degrees of a greyish- heather) aims to benefit red adaptations to cold conditions, white winter coat from a variable by providing a vegetation mosaic, that bring other advantages over greyish-brown summer coat. It is including grass and young heather the species that might compete to associated with upland moorland for food and tall heather for nesting occupy the same environments. In and montane areas in Scotland, cover. This moorland management winter they have thick white , but occupies coniferous forests in is coincidentally highly suitable for the structure, density and colour of much of its global distribution. In mountain hares. In contrast, for which provide excellent insulation, contrast, the Irish sub species (Lepus much of their global range mountain in addition to possible camouflage timidus hibernicus) occupies a range hares are forest-dwellers, where in snowy landscapes. The extremities of habitats down to sea level, and they typically occur at much lower such as feet and ears have especially generally does not turn completely densities of about two to five per km2 thick fur and when at rest, crouching white in winter. [4, 5]. in a ball shape and restriction of the flow of blood to these extremities Populations Survival strategies both conserve heat. Most of the mountain hares on The diet of mountain hares both on mainland Britain are in Scotland, heather moorlands and in the forests with introduced populations in the is highly seasonal. It comprises poor Reproductive flexibility Peak District, several Scottish and quality woody plant material in Gestation length is relatively long at Irish islands and the Isle of Man winter, either heather or other shrubs 50 days, which limits the number of [1]. Globally, the mountain hare and trees, and mainly rapidly growing litters that can be produced to only has a near circumpolar distribution grasses and forbs in summer, to meet one or two in the short northern occurring in both open tundra and the energy and nutrient demands of summers. Female mountain hares coniferous boreal forest (), from reproduction, lactation and growth. are slightly larger than males, and Fennoscandia to Japan [2], with an This flexible foraging strategy means in Scotland they typically attempt isolated population in the European that hares are both browsers (woody to produce three litters, the first Alps. The species comprises at least plant eaters) and grazers (grass being small with one or two young, 15 recognised sub-species, including and herb eaters). Mountain hares followed by two more litters of Lepus timidus scoticus. It is related digest some of their food twice; the usually two to three leverets [6]. The to the Arctic and tundra hares (Lepus process called caecotrophy involves earliest litter for Scottish mountain articus and Lepus othus), and is accelerating the passage of indigestible hares is usually born around early known to hybridise with other hare fibre components of their diet to form April, the product of the first matings species, notably the . the familiar hard hare droppings. that take place surprisingly early Our ‘timid’ hares are not bashful They selectively retain softer, dark in the depths of winter at the end when it comes to spreading their brown paste-like, protein and of January. The success of the early genes. vitamin-rich caecotrophs, which are pregnancies is often low. However, if then re-ingested direct from the anus they do survive, then the early leverets Scottish mountain hares occur at for a second passage through the gut. have a longer growth, and reach their highest densities, of up to Their seasonal digestive adaptations a larger body size than later-born 200 hares per km2, on the heather include special salivary adaptations leverets [7]. This matters in mountain Beasts of the Forest

hares, as larger individuals survive bedraggled and more susceptible to Handbook, 4th edition. The better during their first winter [8] heat loss, should precipitation in Society, pp200-228. and the largest females have greater upland environments shift from the 2. Angerbjörn, A. and Flux J.E.C. reproductive success. traditional cold and dry, to wetter (1995). Mammalian Species, 495, winters. 1-11. The future 3. Watson, A. and Hewson, R. Both climate and habitat change, Mountain hare populations (1973). Journal of Zoology (London), especially woodland expansion, might throughout their range are often 170(2), 151–159. be expected to influence the numbers characterised by regular periodic 4. Shibata, Y. (1985). Annual Report and distribution of mountain hares. changes in density, termed of the Hokkaido Branch, Forestry and The ambitious aims to increase ‘population cycles’. These ‘cycles’, Forest Products Research Institute, woodland cover in Scotland from 17 which occur over a seven to 11- Japan, 60, 56-59. per cent of the land area to 25 per year time scale, are evident in about 5. Lindlöf, B. and Lemnell, P.A. cent by 2050 [9], is likely to result in half the Scottish populations, and 1981. In: Myers, K. & MacInnes, the planting of some areas of heather can confound the monitoring of C.D. (Eds); World Lagomorph moorland that would otherwise long-term population changes. Conference, Guelph, Ontario, 1979, support higher densities of mountain Nonetheless, recent evidence suggests pp. 478-485. hares. Although the mountain hares’ declines in mountain hare numbers 6. Iason, G.R. (1990). Holarctic flexible foraging strategy should in Scotland since the mid-1990s Ecology, 13, 81-89. buffer them from wholesale changes [11, 12, 13]. Mountain hares are a 7. Iason, G.R. (1989a). Oecologia, 81, in habitat to woodlands, overall traditional quarry species and can be 540-546. densities will decrease and the local legally controlled. In one survey of 8. Iason, G.R. (1989b). Journal of and national numbers would be approximately 25,000 hares killed in Zoology (London), 219, 676-680. expected to decline. So a reduction one year [14], ten per cent were killed 9. Scottish Forestry Strategy 2013. in numbers, but not necessarily for forest protection, 40 per cent for Available at scotland.forestry. a reduction in distribution of sport and 50 per cent for attempted gov.uk/images/corporate/pdf/ mountain hares may follow large scale tick control, to limit tick-borne ForestExpansion.pdf afforestation. However, mountain diseases of (see also 15). 10. Jansson, G. and Pehrson, hares should persist if the forests In addition to this shooting pressure, Å. (2007). European Journal of incorporate areas without closed other factors implicated as drivers Wildlife Research, 53, 125–130. canopy, that provide mixed shrub, of rapid declines of hares from high doi: 10.1007/s10344-007-0086- herb and grass ground vegetation. densities include year to year changes 2. https://www.researchgate.net/ in food supply, intestinal parasites publication/225652284_The_ Climate warming would be expected and effects of weather [13, 16]. recent_expansion_of_the_brown_ to reduce the extent of arctic-alpine Although more subtle and difficult to hare_Lepus_europaeus_in_Sweden_ vegetation and lengthen vegetation detect, a long-term gradual decline with_possible_implications_to_the_ growing seasons. The advantages of in mountain hare numbers may, if mountain_hare_L_timidus the mountain hares’ adaptations to verified, represent an equally serious 11. Noble, D.G., et al. (2012). the extreme environments may thus challenge to future mountain hare JNCC, Peterborough. be diminished, and competition, populations. 12. Watson, A. (2013). particularly with other herbivores in north-east Highlands, Paragon, including European hares and Overall the mountain hare is very Northants. Available to read (partial) , may increase [10], extending variable in its ecology, and this at http://tinyurl.com/j9cbxu4 their range and diminishing that of enables it to occupy a broad global 13. Wright, L.J. et al. (2013). mountain hares. Conversely, this may range of habitat and environmental European Journal of Wildlife be compensated by the extension of conditions from open heaths to Research. Available to read at the mountain hares’ breeding season coniferous forests. It has the potential https://www.researchgate.net/ and greater population performance for high population growth rates and publication/258161163_The_value_ by permitting better survival of naturally strong powers of recovery. of_a_random_sampling_design_for_ the earliest litter. Milder autumns In Scotland, the species is likely annual_monitoring_of_national_ may extend the vegetation growth to be flexible enough to withstand populations_of_larger_British_ period, again positively influencing significant habitat and climate terrestrial_mammals survival and reproductive success. change, although its numbers may 14. Patton, V. et al. (2010). Mammal This is supported by the scenario decline as a result of afforestation Review, 40, 313-326. in which Irish hares have adapted, and other environmental changes. 15. Harrison, A. et al..(2010). Journal in the absence of European hares, However, more work is needed to of Applied Ecology, 47(4), 926-930. to a niche which includes lowland, establish how its populations respond 16. Angerbjörn, A. (1983). Finnish often habitats, where they to shooting, and how this might Research, 41, 29-38. maintain high reproductive rates interact with likely changes in habitat for an extended breeding season. and climate. Glenn Iason and Scott Newey Militating against these possible are researchers at the James Hutton positive effects is that mountain hares References Institute, Aberdeen. are not particularly well adapted to 1. Iason, G.R. et al. (2008) In: wet conditions, with fur becoming The Mammals of the British Isles.