Burrowing Owls (Athene cunicularia) have an asynchronous hatch: females begin incubating well before the last eggs are laid, which results in age, size and developmental differences among the members of a clutch. Mating monogamously, for rarely longer then a season, Burrowing Owls have different sex-based roles within a mating pair. Males are typically more territorial than females, and might thus be expected to be generally more aggressive. Males defend their burrows, mates and offspring from predators or competing males while females spend more time incubating and caring for their offspring. I examine the effects of an asynchronous hatch and gender on the behaviour of juvenile Burrowing Owls. Intraspecific interactions between individual owls were observed within an enclosure, in which captive-bred owls are held before release and the relative aggressiveness or submissiveness of each bird was determined during each interaction. The results indicate that although there appears to be an association between the gender and asynchronous hatch on the behaviour of Burrowing Owls there does not appear to be any association between the clutch size and hatch weight on their behaviour.
