29.06.2017 | News
Climate change has prompted three of the most common ungulate species in the Alps - chamois, ibex and red deer - to move to higher elevations in the late summer and autumn. This has been demonstrated by an international research team led by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).
In recent decades, researchers have documented numerous examples of animal and plant species moving to higher elevations due to climate change. This also applies to three alpine ungulate species, as the researchers showed on the basis of a truly unique data set. The Canton of Graubünden's Hunting and Fishing Authority documented more than 230,000 places in the canton where roe deer, red deer, chamois and ibex were shot and killed between 1991 and 2013.
Analysis of these data shows that ibex, chamois and red deer frequented significantly higher ground during this time, elevations that are, on average, 135, 95 and 80 metres respectively higher than those they previously frequented. "This data set is unique and shows that even large, warm-blooded species react to rising ambient temperatures", says Kurt Bollmann from WSL's Conservation Biology research group, co-author of the study published in the science journal Ecosphere. Previously, it had been assumed that this behaviour applies in particular to plants and cold-blooded animals, such as reptiles or insects.
Different from year to year
Ungulate behaviour depends on the animals' living conditions during the hunting season and varies from year to year along with environmental conditions. If the autumn is warm and snow-free, then the places where red deer, chamois and ibex are shot are at higher elevations. These are species that mainly feed on pasture land and alpine grasslands. Roe deer are more closely linked to their territories and to the forest, so their tendency to move to higher ground was weaker.
Over the last 20 years, mean September and October temperatures in the area covered by the study have risen by 1.3°C, a trend which, climate models predict is set to continue. This will change the supply, accessibility and quality of plant food in the mountain forests and Alps, which will force wild animals to further adjust their food intake in keeping with the higher elevations they frequent. The results so far indicate that red deer, chamois and ibex are reacting flexibly to climate change in the Canton of Graubünden. Whether or not this may have longer-term consequences for stocks of these ungulates cannot be concluded with any certainty today. "However, consistent, precise and continuous documentation of kill sites is an important and valuable basis for future research on the impact of climate change on large game species", says co-author Hannes Jenny from Graubünden's Hunting and Fishing Authority.