Strategic placement of Rock Ptarmigan Lagopus mutanests adjacent to boulders

Abstract

CAPSULE: Rock Ptarmigan place their nests adjacent to boulders, in their lee and on their sunnier aspects. AIMS: To investigate the proximity and orientation of Rock Ptarmigan nests in relation to boulders and vegetation height. METHODS: The distances from boulders of 61 Rock Ptarmigan nests and 60 random points were compared. Orientation variables of nests from boulders were analysed with circular statistical formulae. RESULTS: Rock Ptarmigan nests were closer to boulders than random points. The mean orientation of nests relative to adjacent boulders was south-east and the prevailing wind was westerly. Vegetation height at nest sites was taller than at randomly selected sites. CONCLUSION: Rock Ptarmigan which nest next to, in the lee of, and on the south-eastern aspects of boulders, probably gain advantages of protection from the prevailing wind and passive thermoregulation from solar heat. Show more