Niche conservatism is the tendency of species to retain their niche identities over evolutionary time, such that the niche of emergent species is similar to that of the ancestor. Environmental Niche Models estimate environmental suitability based on the relationship between species occurrences and environmental variables. Mountain hares (Lepus timidus spp.) are found throughout Eurasia, mainly in upland areas of Northerly latitudes. In this study we looked at the ecological identities of mountain hare subspecies to investigate niche conservatism and their vulnerability to invasion by the European hare.
All five subspecies of mountain hare had distinct niches. Four subspecies, from Fennoscandia, Scotland and the Alps, were most similar, inhabiting tundra, boreal forest and uplands. They exhibit niche conservatism and are presumed most similar to the ancestral form. The Irish hare was distinct, being consistently distinguished from other mountain hares and is particularly vulnerable to displacement by introduced European hares with which it competes and hybridises. Future conditions under global climate change favour European hares over Irish hares, further facilitating their replacement. The near complete species replacement of the heath hare by the European hare in southern Sweden may be a cautionary tale for authorities in Northern Ireland.
Caravaggi A, Leach K, Santilli F, Rintala J, Helle P, Tiainen J, Bisi F, Martinoli A, Montgomery WI, Reid N (2017) Niche overlap of mountain hare subspecies and the vulnerability of their ranges to invasion by the European hare; the (bad) luck of the Irish. Biological Invasions. 19(2): 655–674. doi: 10.1007/s10530-016-1330-z