Abstract
External drivers of ecological systems have been described at different spatiotemporal scales, but most studies do not explicitly separate between climatic and phenotypic responses in wildlife populations. Horn growth of Alpine ungulates may provide mechanistic understanding of biological responses to environmental changes if well-replicated datasets are long enough. Here, we extend dendrochronological techniques to disentangle effects of climatic and phenotypic changes on Alpine ibex (Capra ibex ibex) populations. After age-trend removal, 42,239 annual horn increments from 8,043 male ibexes and eight distinct populations between ~2000 and 3500 m asl in the European Alps reveal significant interannual to decadal growth coherency back to 1964. March-May maximum temperature variability associated with the North Atlantic Oscillation controls Alpine snow-cover, springtime phenology, and subsequent ibex vitality. Warming-induced horn growth enhancement, increasing hind leg length and an elevational habitat upward shift suggest phenotypic plasticity over the past four decades in the Swiss wildlife icon.
PD Dr. Ulf Büntgen
Swiss Federal Research Institute WSL
Zuercherstrasse 111
CH-8903 Birmensdorf