BEHAVIOR OF ALPINE IBEX (CAPRA-IBEX-IBEX) UNDER THE INFLUENCE OF PARAGLIDERS AND OTHER AIR-TRAFFIC

In summer 1992 we investigated the influence of paragliders and other air vehicles on the behaviour of male ibexes (Capra ibex ibex) in a po pulation of the Swiss prealps. Within a range of 1 200 m ibexes fled m ore frequently from paragliders than from motorplanes, helicopters, sa ilplanes, and jetfighters. Neither group size, previous activity nor t he relative night altitude of the aircraft (above or beneath the obser ved group) was found to have any influence on the reaction. Distance f led after encounters between paragliders and ibex ranged from 30-1200 m (median 650 m) and the changes in altitude while fleeing from 20-500 m (median 200 m). These two parameters were much smaller when reactin g to the other air-based vehicles The daily walking distances were lon ger on days with paraglider activity compared with days without paragl ider activity. Many escape nights went out of the home range normally used by the observed male ibexes. These strong reactions to paraglider s were as yet unknown for ibexes. The conservation implications would be regulation of paragliding in some regions to protect these animals.