Home ranges of adult and juvenile eastern screech-owls: size, seasonal variation and extent of overlap

Adult Otus asio occupied home ranges that averaged slightly under 50 ha in size. No significant differences were detected in home range size of adult males and females during either the breeding season or non-breeding season. Ranges of paired screech-owls overlapped less during the non-breeding season, perhaps reducing competition between members of the pair. While still occupying parental territories, juvenile owls had significantly larger home ranges during the second half of the nine-week pre-dispersal period, and juveniles wandered outside the ranges of their parents more often during this time. Home ranges of juveniles were generally larger following dispersal from parental territories. Shared areas were usually used more by one owl, with only occasional excursions by the other owl. Such behaviour is consistent with the notion that eastern screech-owls defend exclusive areas or territories throughout the year. Adult screech-owls and their young remained in proximity during most of the post-fledging period, suggesting that eastern screech-owls do not divide their broods between parents. -from Authors