European springtime temperature synchronises ibex horn growth across the eastern Swiss Alps.
Bottom Line: Here, we show that variation in annual horn growth (an indirect proxy for individual performance) of 8043 male Alpine ibex (Capra ibex) over the past four decades is well synchronised among eight disjunct colonies in the eastern Swiss Alps.Elevated March to May temperatures, causing premature melting of Alpine snowcover, earlier plant phenology and subsequent improvement of ibex food resources, fuelled annual horn growth.These results reveal dependency of local trophic interactions on large-scale climate dynamics, and provide evidence that declining herbivore performance is not a universal response to global warming even for high-altitude populations that are also harvested.
Affiliation: Swiss Federal Institute for Forest Snow and Landscape Research (WSL), Birmensdorf, CH-8903, Switzerland; Oeschger Centre for Climate Change Research (OCCR), University of Bern, Bern, CH-3012, Switzerland; Global Change Research Centre AS CR, v.v.i., Bělidla 986/4a, Brno, CZ-60300, Czech Republic.Show MeSH
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Mentions: Average monthly accumulated snowcover from January to May is negatively correlated with horn growth in the same year (P < 0.001) (Fig. 4a). The month with the strongest association is April (r = −0.52). Evaluation of actual snowfall level reveals a lower correlation but similar intraannual trends. Early season plant phenology recorded at higher elevation sites and before June (DOY < 150), which is affected by the amount and duration of snowcover, correlates negatively (P < 0.001) with horn growth rate (Fig. 4b), whereas phenological measurements from June onwards (DOY > 150) appear to be less important. The inverse relationship between the onset of high-elevation plant growth and horn increment is best expressed by the blossoming of Alpine coltsfoot (Tussilago farfara), a typical perennial herbaceous in high-elevation meadows (Figure S7). The correlation between annual horn growth and coltsfoot plants from 1982 to present is 0.76 (P < 0.001).
Affiliation: Swiss Federal Institute for Forest Snow and Landscape Research (WSL), Birmensdorf, CH-8903, Switzerland; Oeschger Centre for Climate Change Research (OCCR), University of Bern, Bern, CH-3012, Switzerland; Global Change Research Centre AS CR, v.v.i., Bělidla 986/4a, Brno, CZ-60300, Czech Republic.