# Morbidity and Mortality of Eastern Barn Owls (Tyto javanica) Admitted to a Southeast Queensland Wildlife Hospital

## TL;DR

This study examines the health and survival of eastern barn owls in southeast Queensland, finding that most admissions to a wildlife hospital are due to injuries during their breeding season, likely linked to human activities.

## Contribution

The study provides new insights into the impact of anthropogenic factors on eastern barn owl populations through a detailed analysis of hospital admission records.

## Key findings

- Peak admissions of eastern barn owls occur during winter and spring, coinciding with their breeding season.
- Traumatic injuries are the most common reason for admissions, with 46.61% of owls dying or being euthanized.
- Urban development and human activities are linked to increased risk exposure for the species.

## Abstract

Veterinary wildlife hospitals play a key role in wildlife conservation by not only providing care for wild animals but also recording information about the factors potentially contributing toward a decline in their populations. This paper highlights this role by documenting the anthropogenic and other risk factors affecting eastern barn owls (Tyto javanica) in southeast Queensland, Australia, by reviewing veterinary admission records of these owls to a regional wildlife hospital. Peak admissions occurred during the owls’ breeding season (winter and spring); traumatic injuries (fractures and soft tissue) were overall the most common reason for admission; and while the reason for admission was not reflected in the diagnosis, there was a close relationship between diagnosis and outcome. The overall finding was that anthropogenic activities can have direct effects on the viability of the eastern barn owl.

The eastern barn owl (Tyto javanica), a sub-group of Tyto alba, the most common species of owl in the world, is classified as “of least concern” under Queensland (Australia) legislation but appears to be affected by urban development. Between August 2010 and December 2021, 412 wild eastern barn owls were presented for treatment to the Currumbin Wildlife Hospital. A retrospective study of their medical records shows a strong association between the season and the number of admissions, with a combined total of 80% of admissions occurring in winter and spring (the breeding season for this species) in southeast Queensland. There was no significant association between age and admissions. The most common diagnosis was traumatic injuries, especially in winter and spring. Of all admissions, 46.61% died or were euthanized, 36.17% were transferred to wildlife carers, and 13.83% were discharged from the hospital. We postulate that the breeding season results in an increase in the owls’ activity, in turn resulting in greater risk exposure and increased admissions to veterinary clinics. These findings confirm that and thus provide information about the vulnerability of this species to anthropogenic activities and the implications for outcomes of injured owls.