A male bearded vulture will defend the nest to allow the female to conserve energy and assess his breeding potential.
Breaded vultures defend their nests from conspecifics primarily during the pre-laying period of the breeding season. This may be due to intrasexual competition between males or food competition.
During this period, males attack invaders and use aerial attacks to defend their nests from competitors more frequently than females. This may be so females do not expend excess energy to have more available for mating. Females may also be able to assess the quality and breeding potential of a male through his ability to defend his territory and build a nest.
Sources: (Bertran & Margalida, 2004; Margalida & Bertran, 2005; Margalida, Bertran, Boudet, & Heredia, 2004; Margalida, Garcia, Bertran, & Heredia, 2003; Tenenzapf, 2011)
Image: Susanne Nilsson
