Feeding habits of the barn owl (tyto alba) along a longitudinal- latitudinal gradient in central argentina

Abstract

Se analizó la dieta de la Lechuza de Campanario (Tyto alba) basada en muestras provenientes de nueve localidades a lo largo de un gradiente ambiental de 5º de latitud y 5º de longitud, sobre 500 km en dirección N-S y E-O, en la provincia de Buenos Aires (Argentina). Se identificaron 3251 items presa, principalmente roedores sigmodontinos nativos. Oligoryzomys flavescens fue la presa predominante hacia el noreste del gradiente, mientras que Calomys spp. fueron las presas más comunes hacia el sudoeste. La diversidad y riqueza de presas fue mayor hacia el sur. Los ensambles de roedores consumidos por la Lechuza de Campanario mostraron diferencias significativas entre aquellas localidades ubicadas en los extremos del gradiente, correspondientes a diferentes unidades fitogeográficas.

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 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 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 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 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 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 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 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