A. VON HARDENBERG, B. BASSANO & V. PERACINO
We study changes in size of the population of Alpine ibex (Capra ibex ibex) in the Gran Paradiso National Park, in the Western Italian Alps, by analysing a long series of censuses conductcd in the past forty years. Spring and fall counts are shown to be strongly correlatcd with each other. Spectral analysis of the ibex abundance data indicate two main oscillations, with approximate periods of 3 and 8 years. Meteorological data suggest that the size of the ibex population is limited by winter snow.