Behaviour of hand‐reared orphaned long‐eared owls and tawny owls after release in the wild

Abstract

Two groups of eight long‐eared owls, Asio otus, and eight tawny owls, Strix aluco, which entered a Rehabilitation Centre as nestlings, were studied. When more than 60 days old they were released to the wild. The aim of this study concerns the analysis of their behaviour immediately after release and their adaptation to natural life. The owls were radio‐tagged and followed continuously, also with direct observation, until they disappeared from the area or died. The long‐eared owls, released in an agricultural area with scattered woods, were reluctant to fly frequently and remained mostly in thick vegetation along stream banks or very close to the release pen itself. Nevertheless, they progressively enlarged their home range in a matter of days. Half of them disappeared from the study area within 11 days; three others died in a few days, apparently from starvation, while the last owl was rescued because it fell into a stream. In contrast, the tawny owls had a much better survival rate, as only one out of the eight died because it was preyed on in the early days. The birds remained in the area for a longer time, constantly within the woods, and flew more often. They, too, enlarged their home range but only until day 10, when there was a contraction in size. Thus, inexperienced hand‐reared owlets are able to survive in the wild, but the possibility to cope with the new environment varies greatly between species, possibly due to environmental characteristics.

Keywords:

• Behaviour
• Strigiformes
• Asio otus
• Strix aluco