Differences in the dimensions of diurnal and nocturnal pellets of the barn owl, tyto alba

Abstract

Linear dimensions and weight of barn owl pellets collected at a hay-loft and at a roost-site were examined. Pellets ejected in the hayloft during nocturnal hunting activity were significantly smaller and lighter than those ejected at the roost-site during resting periods in daylight hours. This observation is in agreement with the “pelote diurne et pelote nocturne” theory suggested by Guerin (1932). Linear dimensions and weight of pellets varied from one to another season. Thus, it was suggested that the feeding tactics exhibited by barn owls may affect the content and the linear dimensions and weight of pellets; moreover, it was pointed out that further studies are necessary on pellet characteristics in habitats where barn owl faces spatial and temporal variations in the availability of its most important food resources. © 1996 Taylor & Francis Group, LLC.