Distribution and range expansion of deer in Ireland

1. Throughout Europe, the range of many deer species is expanding. We provide current distribution maps for red deer Cervus elaphus, sika Cervus nippon, fallow deer Dama dama and muntjac deer Muntiacus sp. in Ireland, and estimates of range expansion rates for red deer, sika and fallow deer. 2. There was a considerable expansion in the ranges of red deer, sika and fallow deer between 1978 and 2008. The compound annual rate of expansion was 7% for red deer, 5% for sika and 3% for fallow deer. The total range increase was 565% for red deer, 353% for sika and 174% for fallow deer. The potential implications of these expansions are discussed. 3. There are unknown numbers of red-sika hybrid deer in some parts of Ireland. Range expansion is likely to lead to further hybridizations with implications for the genetic integrity of deer stocks. 4. Sightings of free-roaming muntjac deer were first recorded in 2007. The distribution of confirmed sightings of single and multiple animals in the eastern region of Ireland suggests multiple releases. 5. Deer are already impacting on both the economic and biodiversity values of habitats in Ireland, where, at present, no sustainable deer management policy exists.