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

## TL;DR

This study examines the incubation behavior of a captive Great Grey Owl, comparing unsuccessful and successful nesting events to understand its instinctive and temperature-responsive behaviors.

## Contribution

The study provides the first detailed analysis of Great Grey Owl incubation behavior in captivity, revealing instinctive and thermoregulatory patterns.

## Key findings

- Incubation duration and egg-turning frequency were similar between unsuccessful and successful nesting events.
- The female spent more time on eggs during the unsuccessful nest, suggesting behavioral responses to infertility.
- Ambient temperature influenced incubation behavior, indicating active thermoregulation.

## Abstract

Reproduction is a fundamental aspect of avian biology, with incubation representing a critical phase—especially when only one parent incubates the eggs. Among owls, incubation behaviour remains insufficiently studied, and for the Great Grey Owl (Strix nebulosa), available information is especially limited. This study provides a detailed characterization of a captive female Great Grey Owl’s incubation attentiveness (time on and, time off eggs), egg-turning frequency, and the influence of ambient temperature on this behaviour. This study compared results from an unsuccessful (2008) and a partially successful (2009) nesting event. Prolonged incubation is often associated with infertile clutches, which may indicate adaptive or maladaptive behavioural responses. By comparing incubation behaviours between these two events, this study seeks to advance understanding of the reproductive ecology of the Great Grey Owl and contribute to broader insights into incubation strategies among owls. There were no significant differences in incubation duration (number of days) or egg-turning frequency between these nesting events. Comparable data from wild or other captive Great Gray Owl nests are lacking. Our findings suggest that incubation in Great Grey Owls is instinctive, shaped by evolution and not significantly altered by captivity conditions.

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.