Deaths in free‐living barn owls (Tyto alba)

Pathological examinations were made on 20 free-living barn owls, Tyto alba, that died during winter-spring 1985 Victoria, Australia. Starvation was the likely cause of the deaths with all the birds being in poor condition and markedly underweight (235 to 265 g). The owls had suffered a massive decline in the abundance of their prey, the house mouse, Mus musculus, following the end of a mouse plague. The life cycle of the barn owl makes it susceptible to deaths due to starvation following seasonal variability in prey availability. A secondary finding was localised erosions of the gizzard mucosa associated with infestation by cestodes of the genus Choanataenia.