Red and sika deer in the British Isles, current management issues and management policy

Abstract

The red deer (Cervus elaphus) is one of the most widely distributed species of deer in Europe. Due to its economic value as game species or its negative impacts on forestry, agriculture and conservation areas, most populations are currently managed, with strategies and intensity of the management varying between countries. In Britain, and less certainly in Ireland, red deer have been continuously present since the end of the last glaciation and constitute the largest population of red deer in Europe. Although they thrived in the past when forests were abundant, the current distribution of red deer in the British Isles is uneven, with the largest numbers being found in Scotland and few and more localised populations in England, Wales and the Republic of Ireland. In the British Isles, as in many other parts of Europe, there is a long history of man interacting with deer populations including local extinctions, multiple translocations and introductions of exotic species of deer. Among introduced exotic species of deer, the Japanese sika (Cervus nippon) is the one of most concern. After introduction of small numbers at multiple locations in Britain and Ireland from 1860 onwards, sika have increased in population number and range in areas with good forest cover, and where they overlap with red deer there is a risk of hybridisation. Due to recent increases in numbers and range of red and sika deer, both species pose a range of management challenges which are not easy to solve. In this review we summarise the history and status of these two species in Great Britain and Ireland, describe current management and discuss management options for the future.

A survey of the hybridisation status of Cervus deer species on the island of Ireland

“…Different landscape features are associated with varying gene flow in Scottish red deer (Pérez-Espona et al 2008), and similarly, hybridisation patterns may be influenced by patterns of increasing forestry cover in Ireland. Sika appear to prefer forest habitats, such as commercial conifer forestry, and their expansion can parallel that of its planting (Pérez-Espona et al 2009a). Collaborating with foresters and other landowners could allow deer management to play a role in shaping the layout of future forests in a way that reduces access and suitable corridors for dispersal of the invasive sika and with the leverage that this may also address the potentially economically significant damage that sika may have on Irish forestry.…”

“…The modern red deer population is descended from ancient and recent postglacial introductions by man (Carden et al 2012). Currently, there are around 4,000 phenotypically red deer in Ireland (Pérez-Espona et al 2009a). They are primarily present in the East (Co. Wicklow), the South West (Co. Kerry) and the North West (Co. Galway north to Co. Donegal) and have shown a 6.5 % range expansion from these sites over the last 30 years (Whitehead 1964;Carden et al 2011).…”

“…Over the last 30 years, this invasive species has expanded its range at around 5 % per annum from populations in the East, South West and North West of Ireland (Carden et al 2011). The extent of hybridisation in the North West has not been well studied, and the presence of red-sika hybrids in this region is suspected (Harrington 1973;Pérez-Espona et al 2009a;Carden et al 2011) but there is no definitive evidence of it to date. Despite a long period of sympatry (1864 to present), no phenotypic hybrids have been reported in Co. Kerry.…”

Distribution and range expansion of deer in Ireland

“…Lone young individual sika males disperse first and can appear in areas with no established sika, and join red deer populations (Bartoš 2009, Swanson & Putman 2009). As proposed in Britain (Pérez‐Espona et al. 2009), selective culling of these ‘pioneering’ sika males should be encouraged if there is a threat to the genetic purity of red deer populations, and this has been the recommended management strategy for County Kerry (McDevitt et al.…”

Assessing the impact of past wapiti introductions into Scottish Highland red deer populations using a Y chromosome marker

“…As with other many game species in Europe, there is a long history of Scottish red deer populations being supplemented by the introduction of related exotic species (Pérez-Espona et al 2009b). These included introductions of North American wapiti (Cervus elaphus canadensis or Cervus canadensis), a species two to three times heavier than Scottish red deer, in an attempt to improve body and antler size for trophy hunting (Whitehead 1960(Whitehead , 1964.…”