by Fiona Mathews, Mammal Society Chair and Professor of Environmental Biology at University of Sussex
This article first appeared in British Wildlife magazine in March 2021
The Mammal Society, along with our partners NatureScot, British Trust for Ornithology, The James Hutton Institute and the Game and Wildlife Conservation Trust, is launching a new Volunteer Mountain Hare Survey in Scotland this spring. If you are a hill-walker, a fell-runner, or perhaps a rider or bird-watcher, we would love you to take part.
The Mountain hare Lepus timidus must be one of our most iconic native species. At this time of year, the animals are usually sporting their white coats — highly effective camouflage on snowy hillsides — before changing back to a more familiar grey-brown pelage in the spring. Climate change, and consequent altered snowfall patterns, have been proving a challenge for the species, with white (or even mottled) coats being a marked disadvantage when snow fails to materialise (Pederson et al. 2017). The completeness of the change to white varies considerably between individuals and it is likely that strong selection pressure will be acting in favour of those that change least if snow fall reductions continue (Mills et al. 2018). In Ireland, the subspecies L. timidus hibernicus (also known as the Irish hare), rarely turns completely white in winter, though it usually has white fur on the feet and belly.
Globally, the brown hare Lepus europaeus is found at more southerly latitudes than the mountain hare, and was probably introduced into Britain by the Romans. Along with deforestation, competition with this more recent interloper is likely to be one of the major reasons why the distribution of mountain hares in Britain is so restricted. The brown hare was introduced into Ireland in the 1970s (who thought that was a good plan?), and it has been expanding its range ever since. The evidence points to it being able to outcompete the native species, raising concerns that it could eventually displace it (Reid 2011, Caravaggi et al. 2015). In Britain, the only population outside Scotland is in the Peak District — the sole survivor of several Victorian attempts to establish mountain hares for hunting in England and Wales. Technically, the Peak District hares are considered non-native because they are beyond the range occupied during historical times (post-1500).
Assessments of the conservation status of the mountain hare are difficult. Population sizes are naturally unstable, and there is some evidence that densities could follow a cyclical pattern in some areas. However, detailed longitudinal data that account for observer effort are largely lacking. The distribution of the species outside core areas is also poorly defined. In Scotland, there is an added political dimension because the highest densities of mountain hares are often found on heather moorland managed for shooting. (In continental Europe, mountain hares are generally associated with woodland, whereas in Scotland, they are usually found in more open habitats and at elevations above 300m). Concern about reports of large numbers of hares being killed has led to the Scottish Government bringing in new legislation, and consultation with stakeholders is currently taking place.
Britain’s Red List for terrestrial mammals classes mountain hare as Near Threatened, with a population size of 135,000 (but note the very wide plausible intervals of 81,000 to 516,000 owing to the lack of reliable data). The only substantial dataset covering the range of the species is the National Gamebag Census, but interpretation is difficult because the amount of shooting effort is not quantified. Two studies based on transect counts on moorland have reached contrasting conclusions: one suggests that they are declining rapidly, particularly on grouse-moors, and the other suggests that they are stable (or even increasing) in these habitats (Wilson and Watson 2018; Hesford et al. 2019).
The clear need for better monitoring has led to the development of a scheme based on night-time transects using spot-lights (lamping) that is now undertaken by landowners, supported by the Game and Wildlife Conservation Trust (GWCT). However, these surveys are largely focused on the Central Highlands: more information is urgently needed across the rest of the species range in Scotland and where lamping is not practical (https://www.nature.scot/naturescot-research-report-1076-designing-monitoring-scheme-mountain-hare-lepus-timidus-scotland). This is why we have designed the new national Volunteer Mountain Hare Survey. There will be some overlap with areas covered by the lamping surveys (so we can judge the comparability of the methods), but most of the data in the new survey are expected to come from Scotland more widely.
The survey is easy to carry out, with the information being recorded on the Mammal Society’s Mammal Mapper app (which works even when out of mobile signal range). The big advantage of using the app is that your route is automatically recorded, which means that we can identify locations where mountain hares are absent, as well as where they are present. Many hill walkers will already be familiar with the sight of mountain hares bounding off into the distance; we are also producing a training video and other materials that will be available shortly on our website, to help people who are less familiar with the species to distinguish it from rabbits and brown hares. Any hares seen at high elevations are highly likely to be mountain hares, and any in winter white coats are impossible to confuse with other species.
There are two ways to get involved in the project. First, you can simply turn on the Mammal Mapper app when you are out and about, with the location and route entirely chosen by you. Alternatively, you can sign up with the British Trust for Ornithology to monitor a 1km grid square. To help volunteers who have an interest in recording birds as well as mammals, we are currently adding upland birds to the Mammal Mapper as an optional add-in. Please keep an eye on our website for updates!
Caravaggi A, Montgomery WI, Reid N. Range expansion and comparative habitat use of insular, congeneric lagomorphs: invasive European hares Lepus europaeus and endemic Irish hares Lepus timidus hibernicus. Biological Invasions. 2015 Feb 1;17(2):687-98.
Hesford N, Baines D, Smith AA, Ewald JA. Distribution of mountain hares Lepus timidus in Scotland in 2016/2017 and changes relative to earlier surveys in 1995/1996 and 2006/2007. Wildlife Biology. 2020 Jun;2020(2).
Mills LS, Bragina EV, Kumar AV, Zimova M, Lafferty DJ, Feltner J, Davis BM, Hackländer K, Alves PC, Good JM, Melo-Ferreira J. Winter color polymorphisms identify global hot spots for evolutionary rescue from climate change. Science. 2018 Mar 2;359(6379):1033-6.
Pedersen S, Odden M, Pedersen HC. Climate change induced molting mismatch? Mountain hare abundance reduced by duration of snow cover and predator abundance. Ecosphere. 2017 Mar;8(3):e01722.
Reid N. European hare (Lepus europaeus) invasion ecology: implication for the conservation of the endemic Irish hare (Lepus timidus hibernicus). Biological Invasions. 2011 Mar 1;13(3):559-69.
Watson A, Wilson JD. Seven decades of mountain hare counts show severe declines where high‐yield recreational game bird hunting is practised. Journal of Applied Ecology. 2018 Nov;55(6):2663-72.