Genetic Integrity of the Red Deer in Ireland

Red Deer, Cervus elaphus, : Two Hinds (Left) and a Stag (Right)

The origin of the Red Deer (Cervus elaphus) in Ireland is obscure. Skeletal remains of animals have been found and dated from 27,730 years before present up until 11,790 years before present when evidence for the deer disappears until 4,190 years before present (1). Whatever the reason for this 7,500 year gap, it indicates that the current population of Red Deer in Ireland is descendant from human mediated introductions: indeed the earliest record of such an event is in 1246 when Red Deer were moved from the Royal Forest in Chester, England to the then Royal Forest, Glencree, Co. Wicklow (2). The Red Deer population in the Killarney National Park was in the past believed to be the only surviving animals derived from the post glacial population (3). While no evidence exists for this, the origin of the Killarney population is still unknown.

Red Deer Stag, Cervus elaphus

The Red Deer can mate with its close relative the Sika Deer (Cervus nippon), an animal introduced to Co. Wicklow in 1860 (Powerscourt Estate) and then to Co. Kerry (4). While such hybridisation can impart new levels of fitness to a population (5), in this case preservation of the 'pure' stock of Red Deer is of paramount importance (6). Recent investigations into the levels of hybridisations in the Irish Red Deer population using microsatellite and mitochondrial DNA markers found that of 85 Red Deer tested, 10 were found to be Red/Sika hybrids with the other 75 being 'pure bred' individuals (6). While these levels of hybridisation were lower than expected, steps should be taken to prevent contact between the two species, with recommendations including culling of Sika stags entering Red Deer strongholds (7).

Reference:

1. Woodman et al., 1997 Quaternary Science Review 16 pp. 129–159
2. Moffat, 1938 Proceedings of the Royal Irish Academy 44B pp. 61–128
3. Staines et al., 2008 Mammals of the British Isles (Harris and Yalden, Eds.) pp. 573–587
4. Powerscourt, 1884 Proceedings of the Zoological Society of London pp. 207–209
5. McDevitt et al., 2009 Molecular Ecology 18 pp. 665–679
6. McDevitt et al., 2009 Mammalian Biology 74 pp. 263–273
7. Perez-Espona et al., 2009 Mammalian Bilogy 74 pp. 247-262