Hatching asynchrony, sibling aggression and cannibalism in the Bearded Vulture Gypaetus barbatus

摘要: We report data on laying and hatching asynchrony in the Bearded Vulture Gypaetus barbatus, provide first detailed description of provisioning nestlings, sibling aggression cannibalism. The results suggest that brood reduction was mediated through age size differences between siblings, which resulted superior competitive ability older chick. Thus, occurred starvation facilitated directly by chick’s aggression. support hypothesis second egg probably functions as insurance case does not hatch. insurance-egg is supported following facts: 1) three six breeding attempts, produced a chick when failed to hatch or died young. At least two these B chicks fledged; 2) most failures occur during period thus value last-hatched eggs would be especially important this species; 3) clutch replacement, an alternative egg, relatively uncommon species 4) interval (5‐7 days) (5‐8 are longest recorded any raptor, suggesting they might represent adaptive mechanism facilitating rapid loss if one hatches. In great majority bird with obligate (those more than 90% die, Simmons 1988), parents produce eggs, then fledge only cases, responsible for (Mock & Parker 1997). Adaptive strategies may either asynchronous decrease last-laid eggs. Large generally have small final supporting (Edwards Collopy 1983). Two main hypotheses gained recent attention discussion about significance siblicide ‘insurance hypothesis’ proposes (Meyburg 1974, Stinson 1979, Mock