Cold weather habits
La variable hare (Lepus timidus), a typical inhabitant of medium and high Alpine altitudes, is a species potentially affected by ongoing climate changes. It is a mammal adapted to living in the high mountains or at extreme latitudes and owes its name to the seasonal change in color of its coat: during the winter it changes into an unmistakable and camouflage white coat, which is why it is also known as a white hare. Well adapted to cold climates, it could be affected by the increase in temperatures as well as by the possible expansion, towards higher altitudes, of the range of the European hare, Lepus europaeus. The latter species, similar to the variable hare but more generalist and adapted to low altitudes, could rise in altitude and always overlap with the variable hare, with which it competes.
Presence and distribution
A study by ISPRA and the University of Turin, in collaboration with the Gran Paradiso National Park, therefore examined the changes in the presence and distribution of both species in an Alpine valley, comparing data from 2009 and 2021, quantifying for the first time what the impacts of over a decade of climate change could be on the two hare species. Analyzing the data collected in the same locations 12 years later, the study demonstrated how the variable hare was more common in 2009, especially as the altitude increased, in areas with pioneer vegetation and in rocky areas. However, the presence of the European hare has also been documented at high altitudes, in landscapes atypical for this lowland species. The area of overlap between the two species was quite large and the presence of European hares increased over time, even at medium-high altitudes. The areas reserved for the variable hare seem limited to a very narrow and high altitude band.
Increase in temperatures
The ongoing climate changes caused mainly by greenhouse gas emissions produced by the use of fossil fuels are increasing the earth's temperatures. Among their effects, research has documented direct and indirect impacts on ecosystems and animal and plant species. In particular, climate change can affect the distribution of species in several ways. As temperatures rise, species tend to move to higher latitudes or altitudes, in search of cooler climatic conditions. Alpine species are more at risk as altitudinal migration is limited by the height of the mountains themselves. For numerous animal species, substantial upward shifts in distribution limits have already been documented over the last century, with a reduction in their diffusion at low altitudes and a general loss of range. Variations in the geographic distribution of species can also have cascading effects on interactions between different species. (Source ISPRA).