Feeding habits of the Barn Owl (Tyto alba) along a latitudinal-longitudinal gradient in central Argentina

LEVEAU, L., P. TETA, R. BOGDASCHEWSKY Y U. F. J. PARDIÑAS

ORNITOLOGIA NEOTROPICAL

NEOTROPICAL ORNITHOLOGICAL SOC

Año: 2006 vol. 17 p. 353 - 362

1075-4377

We studied the food habits of the Barn Owl (Tyto alba) based on samples from nine coastal localities along an environmental gradient of 5º of latitude and 5º of longitude, about 500 km N-S and EW, in the Buenos Aires Province (Argentina). We identified 3251 prey items, mainly native sigmodontine rodents. Oligoryzomys flavescens was the predominant prey species in the diet of the owls in the northeastern part of the gradient, while Calomys spp. were the most common prey species toward the southwestward. Prey diversity and total vertebrate prey richness were greater towards the south. The rodent assemblages consumed by Barn Owls showed significant differences among the localities settled at the opposite extremes of the gradient, corresponding to different phytogeographic units.