Vigilance levels in European Wigeon - sexual differences

Abstract

Male Wigeon Anas penelope, feeding on a reserve in south-west Scotland, are generally more vigilant than female birds. The divergence in vigilance rates tends to increase in riskier situations. In small flock sizes, no difference was detected except in solitary pairs, when males were more than twice as vigilant as their mates. Individual vigilance rates decrease exponentially with increasing flock size. The most likely reasons for the sex difference are the conspicuous male plumage and mate guarding.