Incubation and Nesting Behaviour of the Great Grey Owl (<em>Stix Nebulosa</em>) During Infertile Eggs and Successful Hatching

Owl incubation behavior, as an aspect of their ecology, remains poorly understood. To date, no studies have documented the incubation patterns of the Great Grey Owl, and existing knowledge of its breeding behavior remains limited. In the present study, we used video recordings under aviary conditions at the Poznań Zoological Garden to quantitatively assess incubation attentiveness in the Great Grey Owl, enabling us to reliably document and distinguish parental behaviors in this species. The aim of this study is to provide a detailed characterization of incubation behavior in the Great Grey Owl by quantifying several aspects of nest attentiveness (incubation attentiveness, nest ventilation time, egg-turning frequency, and the influence of ambient temperature on incubation behavior. These variables were analyzed in relation to two reproductive outcomes: nests containing infertile eggs and nests that resulted in successful hatching. Overall, we did not find significant differences between these cases in terms of incubation duration (number of days) or egg-turning frequency. However, we observed that incubation attentiveness was significantly higher during the incubation of infertile eggs, despite the total number of incubation days remaining unchanged. We also found that ambient temperature influenced incubation behavior, with females adjusting their attentiveness in response to changing weather conditions, suggesting active thermoregulation. Our findings indicate that incubation in Great Grey Owls is largely instinctive—likely shaped by evolutionary processes—and not significantly altered by captivity conditions.