Assessing the effectiveness of bird rehabilitation: temporarily captive-reared Little Owls (Athene noctua) experience a similar recruitment rate as wild birds

Abstract

A large number of young birds are caught each year shortly after having left the nest and subsequently brought to bird care centres. These birds are temporarily hand-raised before release. To date, the effectiveness of this action has remained largely unassessed. Here we monitored the fate of 119 rehabilitated Little Owls (Athene noctua) and found that the recruitment rate of the rehabilitated birds was similar to that of wild birds (11.8% of 119 rehabilitated birds vs. 10.7% of 382 wild fledglings). The timing of release, i.e. whether rehabilitated birds were released in the autumn or in the following spring, did not appear to affect recruitment probabilities, although birds released the following spring showed a tendency for reduced breeding success and dispersal compared to wild birds, suggesting that autumn releases may be more favourable.