Incubation Behaviour of a Captive Female Great Grey Owl (Strix nebulosa) for an Unsuccessful and a Successful Hatching

Great Grey Owl incubation patterns; knowledge of its breeding behaviour is limited. We used video recordings of a captive nesting female at the Poznań Zoological Garden to quantify incubation attentiveness (time on and off eggs) and other behaviours including egg-turning frequency, and the influence of ambient temperature on these behaviours. We also compared these behaviours for an unsuccessful nest (2008) and a partially successful (2009) nest. There were no significant differences between years for incubation duration (number of days) or egg-turning frequency. The female spent more time on eggs for the unsuccessful nest despite the total number of incubation days remaining unchanged. Ambient temperature influenced incubation behaviour, with the female adjusting its attentiveness (time on and off eggs) suggesting active thermoregulation. Our findings indicate that incubation in Great Grey Owls is instinctive and not affected by being held captive.