Bird surveys reveal population changes - for mammals!
October 2013. A new study, published in the European Journal of Wildlife Research, looks at the first 18 years' data collected by Breeding Bird Survey volunteers to investigate how the populations of nine species of common mammal have changed at national and regional scales during this time.
Mammals studied
Bird surveyors have given the clearest picture yet of how nine of our common mammal species are doing. These are Grey Squirrel, Rabbit, Brown Hare, Mountain Hare, Red Fox, Reeves' Muntjac, Red Deer, Fallow Deer and Roe Deer.
Deer all increasing
The results show that populations of four deer species (Roe Deer, Reeves' Muntjac, Fallow Deer and Red Deer) all increased between 1995 and 2012. This is of concern given evidence that increased deer browsing in woodland can reduce the vegetation understorey and impact negatively on other woodland wildlife.
Rabbits in decline - Hares mixed - squirrels good & bad
In contrast, Rabbit numbers declined by 48% over the same period, following a large increase in Rabbit numbers prior to 1995 revealed by other studies. There are also fascinating regional differences in the trends for some species; for example, Brown Hare populations have declined by 50% in Northwest England but increased by 70% in the East Midlands. A significant increase in non-native Grey Squirrel numbers in Northwest England may be of concern, in relation to their potential impacts on native Red Squirrels that are now largely confined to Scotland.
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