Almost one in five of British mammal species face a high risk of extinction, according to the first comprehensive review of their populations for more than 20 years launched today by The Mammal Society and Natural England. The red squirrel, wildcat and the grey long-eared bat are all listed as facing severe threats to their survival.
Fact file:
Hedgehog – Current estimated population of 522,000 is 66% lower than estimated in the previous comprehensive review in 1995. Hedgehogs are struggling because the insects they prey upon are declining from changes in agricultural practice and pesticide use, human influence through road accidents and loss of nesting habitat. They may also face increased threats from badgers whose population has doubled in the same period to around 562,000.
Red squirrel – There has been marked decline in the distribution of red squirrels since 1995 which has been linked to ever increasing grey squirrel numbers. The invasive species now outnumber the red squirrel 10:1. Disease epidemics, including squirrel pox which is transmitted by grey squirrels, and competition for resources are factors for reducing red numbers as well as an increase in the planting of Sitka spruce trees — native to North America — which are less favourable to red squirrels.
Rabbit – The rabbit is classified as globally threatened, and in Britain its population is likely to have declined by about 9% since 1995, now standing at around 36 million. Other surveys, based on the numbers of animals culled, or primarily focused on recording bird numbers have recorded larger drops of 24% between 1995 and 2014 and 48% between 1995 and 2012 in Britain respectively. Localised populations can be extremely variable depending on scale of disease outbreaks, particularly of rabbit viral haemorrhagic disease and myxomatosis, and large-scale surveys are needed to understand the status of the British population more clearly. The impact of culling on population size could be waning because of reduced demand for rabbit meat and fur.
Orkney vole — There is an urgent need for more information on this small animal. It was introduced to the Orkneys in Neolithic times, and is now an important part of the local ecosystem, where it is prey for numerous birds of prey including short-eared owls and hen harriers. Not only has the vole suffered from changes to farming practices, but it is now at severe threat from stoats which have introduced to the islands in the last decade.
Water vole – From a 1995 population of more than 1 million, water vole numbers now estimated to be just a tenth of that. Threats from the American mink and changes in land management, including wetland drainage, arable cultivation and watercourse canalisation, are believed to have been largely responsible for their steep decline.
