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This study investigated the relationship between landscape structure at different distances from the Drava River in South Hungary and the food composition of the Common Barn-owl. Pellets were collected from 15 villages between 2006 and 2008. Based on the CORINE land cover elements, five land use types were determined, and five landscape metrics were calculated to compare land use and landscape structure in the three distance zones. There were significant differences in the Shannon and Simpson diversity of small mammal assemblages between the three areas. A positive relationship was detected between the distance categories and the abundance distribution of the Striped Field Mouse and Field Vole. The relative abundance of the Striped Field Mouse in the diet of Common Barn-owl was influenced by the increase in the mean perimeter/area ratio and the mean of the contiguity index. The value of the trophic level index was negatively influenced by the decrease in crop patches and the increase in pasture and grassland areas, which land use types facilitate the distribution of insectivores. Our results suggest that landscape characteristics influence prey occurrence in hunting areas and the frequency-dependent availability of small mammal prey, which determines the resource utilization of Common Barn-owl. [ABSTRACT FROM AUTHOR]

As an opportunistic predator, the Common Barn-owl (Tyto alba) proved to be an appropriate model organism to survey the composition of small mammal assemblages. This study analysed barn owls’ pellet samples from 14 localities containing 34 animal taxa and 4,088 prey items in two years (2015–2016). Two groups of samples (7–7 localities) were separated based on the dominance of semi-natural habitats and agricultural lands. Rarefaction analysis proved that the species richness and diversity of barn owls’ diet were significantly higher in semi-natural landscapes. The multiple regression analysis between PCA scores showed that in the agrarian landscape the abundance of generalist species was influenced by the proportion of forests, while the value of the trophic level index was determined by the size of arable fields. In the case of semi-natural landscapes, the abundance of the synantrop guild and generalist species, especially S. araneus and A. agrarius, was influenced by the proportion of urban areas, the number of habitats and the size of arable fields. The results of this study suggested that the small mammal consumption of the Common Barnowl is significantly different in the two landscapes, which reflects the impact of habitat heterogeneity and agricultural activity on prey availability. [ABSTRACT FROM AUTHOR]

Changes in land use affect the life of small mammals and the owls that prey on them. The aim of the present work was to follow changes in the composition of the common barn-owls' prey and the landscape structure of their hunting areas. In 2007 and 2016, we collected owl pellets in the whole area of Baranja region but samples from both periods originated only from 10 sites. The diversity of small mammals in the prey was similar in both years, while common vole (Microtus arvalis) dominated with over 60%. In pellets collected in 2016, we found significantly more bicolored shrews (Crocidura leucodon), lesser white-toothed shrews (Crocidura suaveolens) and yellow-necked mice (Apodemus flavicollis), while the proportions of harvest mouse (Micromys minutus) and eastern house mouse (Mus musculus) were significantly lower than in the previous sampling. The landscape structure of hunting areas has hardly changed over the decade; therefore, the temporal variations in the owls' diet composition may have been caused by changes in farming practices such as the frequent mowing of meadows, the regulation of the use of pesticides, the depopulation of villages and also the effects of extreme weather. [ABSTRACT FROM AUTHOR]

This study investigated the dietary niche of the Barn Owl (Tyto alba) in an intensively farmed landscape, based on pellet samples from 12 nesting pairs containing 25 animal taxa and 1,994 prey items after the breeding season in 2016. Based on land use categories of the buffer area around each nest, three landscape types (agricultural, mosaic, urban) were considered, to analyse the diet composition and food-niche parameters. Niche breadth was calculated at the local and landscape level. Small mammals were the most frequent in the diet than other prey in each of the landscape types. The Common Vole (Microtus arvalis), considered to be an important agricultural pest was the most numerous prey in all landscape groups. The trophic niche of Barn Owl varied between 0.69 - 0.86 at the local level, and the overall value of niche breadth was significantly higher in the urban than in the other two landscape types. Our results showed that the increase of Common Vole frequency lead to a decrease in niche breadth; significantly negative relationship was detected between these parameters. Despite differences in niche breadth, similarly high niche overlaps were detected by the randomisation test in the three landscapes. Our results suggest that the diet composition of Barn Owls, mainly their food-niche pattern, reflected prey availability in the comparison of the studied landscapes, which pointed out that it is necessary to examine the dietary difference of Barn Owls at the finer scale of land use. [ABSTRACT FROM AUTHOR]

Coexistence of predator species often depends on behaviours or preferences that result in spatiotemporal reduction of competition. In this study, the diets of coexisting barn owls (Tyto alba) and eagle owls (Bubo bubo) in an agricultural landscape of SE Bulgaria were compared. White-toothed shrews (Crocidura spp.), voles (Microtus spp.) and mice (Mus spp.) were the main prey of barn owl (86.3% by number, 81.2% by biomass) with significantly different frequencies in annual diets. The principle biomass (64.8 ± 6.2%) of the significantly different eagle owl annual diets comprised much heavier prey such as white-breasted hedgehog (Erinaceus roumanicus), European hare (Lepus europaeus) and non-passerine birds of wetlands and open habitats. The two owl species preferred and hunted on different prey size groups in the same territory, and this difference explained the low level of food competition (6.0 ± 3.6% diet overlap according to prey biomass). Voles were the only prey of the two owls with significantly different frequencies for the annual diets in intraspecies comparisons. The proportions of voles in both diets showed similar trends during the study. Eagle owl predation on barn owls was slightly affected by their coexisting breeding despite the high levels of food stress of eagle owl. These findings provide insight into how preying habits can predict successful coexistence of potentially competing predator species. [ABSTRACT FROM AUTHOR]

This study of the diet of Barn Owl Tyto alba analyzed pellets containing 18,810 prey specimens. Small mammals (98.2% by number, 97.5% by biomass) dominated, while birds, reptiles, amphibians, and insects constituted a negligible portion of the diet (1.8% by number, 2.5% by biomass). Voles (Microtus spp.) were the most numerous prey (35.3 ± 14.4%, range 14.6%-67.1%) in 9 localities (69.2%, n = 13 individually studied localities) and dominated the biomass in all diets (51.4 ± 14.1%, range 27.4%-78.2%). The lesser white-toothed shrew (Crocidura suaveolens) (20.8 ± 7.6%, range 7.3%-32.8%) was the most frequent prey in the other 4 localities (30.8%). The breeding localities with more similar proportions of habitats in their hunting territories had significantly higher diet overlaps (r = 0.336, P < 0.01). The amount of wetlands and the indices of habitat heterogeneity and topographic relief among the landscape characteristics of the hunting territories significantly influenced diet composition according to redundancy analysis. Larger areas of wetlands correlated with higher predation on wetland mammal species, as well as the European pine vole (Microtus subterraneus) and white-toothed shrews, and thus with broader food niche breadth. [ABSTRACT FROM AUTHOR]

The article presents a study which examined bat predation by the barn owl Tyto alba in a hibernation sites of bats. It states that based on numerous studies of owl pellets, bats are not commonly represented in the prey of the barn owl and usually make up less than 1% of the prey individuals. It mentions that the prey remains of the barn owl from the fortress Dömitz, southeast of Mecklenberg-Western Pomerania, Germany, were investigated. It notes that the high frequency of bats from the 2002 sample led to a total percentage of bats of almost 39% and bats were clearly dominant over other potential prey groups. It adds that the findings reveal that Tyto alba is an opportunistic but no selective hunter of bats.