The Irish hare is currently classified as a sub-species of the mountain hare (Write Back, August 9).
However, genetic research by Queen’s University, Belfast, suggests that it may warrant reclassification as a full species, Lepus hibernicus.
Scientists have numerous concepts by which to define a ‘species’, the most prevalent being the ‘biological species concept’; a discrete group of interbreeding individuals. Nevertheless, many discrete species' can interbreed to create most usually sterile, but on occasion fertile, offspring. The latter is the case between Irish and European hares.
Offspring of female mountain hares that crossbreed with male European hares not only resemble their fathers but have a predisposition to backcross with European hares. Thus the reproductive effort of the native hare is wasted and it’s population subsequently dwindles. Furthermore, competition for resources between the species may further compound the native’s demise.
In contrast, grey squirrels both out-compete and transmit a deadly disease (parapox) to red squirrels, but do not hybridise with them. Nevertheless, parallels can be drawn between the invasiveness of grey squirrels and European hares and their potentially devastating effect on native species.
Dr Neil Reid
Queen’s University, Belfast