The prey composition of the Barn Owl(Tyto alba)with respect to landscape structure of its hunting area (Zala County, Hungary)

Abstract

The prey composition of the Barn Owl (Tyto alba) can be monitored indirectly by pellet analysis and we used this method to investigate less known small mammal species of Zala County. The number and abundance of small mammal species depend on the structure of the landscape of Barn Owls’ hunting area, therefore we analysed landscape features in the surrounding circles with 2 km radius around the sampling sites. In 2016 we collected 1106 pellets from 13 sampling localities. From the pellets we identified 21 species of 3022 individuals of small mammals (more than 98% of prey). Among the 21 species there was the rare Parti-colured Bat (Vespertilio murinus) and a new species for the county the Steppe Mouse (Mus spicilegus). Positive correlation was found between the diversity of the small mammal fauna of each sampling site and the landscape complexity (number of the landscape patches) of the Barn Owl hunting area. Relative abundance of the Wood Mouse (Apodemus sylvaticus) showed positive correlation with the number of landscape patches, while the abundance of the Lesser White-toothed Shrew (Crocidura suaveolens), the Miller’s Water Shrew (Neomys anomalus), the Striped Field Mouse (Apodemus agrarius) and the Harvest Mouse (Micromys minutus) was higher in hunting areas with more homogenous landscapes. Significant correlations were found between the relative abundance of some small mammal species and the landscape structure of the potential hunting area of owls that confirmed the consistency in habitat preference of some species. Our results proved that the prey-composition of Barn Owls reflects the land use through the distribution and abundance of small mammal species, therefore this method is suitable for ecological analyses of landscape.

Food-niche pattern of the Barn Owl(Tyto alba)in intensively cultivated agricultural landscape

“…The percent frequency of Striped Field Mouse as a generalist species was significantly higher in the urban landscape. With respect to the relative proportion of this species, our results are consistent with other studies which described the Striped Field Mouse as a permanent but non-dominant prey in the Barn Owl's food composition in the southern part of the Transdanubian region (Horváth et al 2005, Purger 2014, Szép et al 2017. Some studies have also pointed out that this rodent species is rather a supplementary component than a crucial or important alternative prey in the diet of Barn Owls (Ruprecht 1979, Milchev 2015.…”

Connection between prey composition and the landscape structure in the hunting area of Barn Owl’s (Tyto alba) in Baranja (Croatia)

“…The numbers of specimens extracted from one pellet were determined based on the number of skulls and the related mandibles. The taxonomic determination of small mammals was performed on the basis of skull and mandible parameters (3).…”

“…For landscape structure and mosaic analysis we used the 1: 50 000 map of the CORINE Land Cover Project from 2006 (10). On this map circular areas with 2 km radius around the sampling sites were considered as the hunting areas of Barn Owls (3). In these circles we examined the distribution of CORINE land cover habitat classes (e.g.…”

“…The composition and abundance of the small mammal communities of the Barn Owl's hunting area can be influenced by landscape structure (2). By examining the diet of Barn Owls we can make conclusions about the landscape structure of their hunting area, as the abundance of small mammal species from pellets reflects the distribution of their habitats (2,3). Owl pellet analysis is therefore not only used to better understand the diet of owls, but also as an indirect method for small mammal fauna surveys and more often in ecological studies.…”

Temporal changes in the diet composition of the Eastern Imperial Eagle (Aquila heliaca) in Hungary

“…Although direct observations or remote camera systems can provide the most accurate datasets for studying the diet of raptors during the breeding season (Takeuchi et al 2006, Sánchez et al 2008, such investigations are expensive and they can only gather data from a very limited number of territories. Therefore, usually indirect methods are used for diet analyses, such as the collection and analysis of pellets is the most widespread method for the diet analyses of owls (Halliez et al 2015, Hámori et al 2017, Szép et al 2017. In case of diurnal raptors, the data derived from pellets can be significantly completed with the analyses of other prey remains, such as bones, hairs and feathers found around nest sites and roosting trees (Watson et al 1993, Balogh 1998, Preston et al 2017.…”