Seasonal variation in the diet of the little owl, Athene noctua in agricultural landscape of Central Poland
Romanowski, Jerzy; Altenburg, Dania; Zmihorski, Michal
We studied the diet of the little owl, Athene noctua, in an agricultural lands of Central Poland. In total, 642 pellets were collected in the years 1995-1997 and 3090 prey items were identified. In the diet, Coleoptera dominated by number (62.4 %), but vertebrates dominated in terms of biomass (98%). The most frequently found vertebrate prey was the common vole, Microtus arvalis, and Muridae. Birds and amphibians were found in pellets only occasionally, mostly in summer. Contribution to the main prey categories of little owl diet differed seasonally: mammals were preyed upon more frequently in winter, while invertebrates in autumn. Redundancy analysis (RDA) revealed preferences of little owl to common voles in winter and summer, house mouse (Mus musculus) in spring, and Apodemus mice in autumn-winter periods. Share of particular invertebrate groups in the diet was not random over the year. Carabid beetles were preyed upon all year round and together with cantharid larvae made up an important component of the winter diet. The high proportion of invertebrates as well as the presence of synantropic rodents in the winter diet suggests that in the winter, little owl utilise buildings as hunting sites. From the analysed pellets we noted that a high frequency of lumbricid earthworms, was present in up to 53% of the pellets in the autumn. Assuming different numbers and individual body mass of an earthworm, we estimated that the contribution of lumbricids may reach from 5 to 40 % of the total prey biomass consumed by little owl in autumn.
predation on invertebrates; insects; raptors; voles; earthworms; Lumbricidae
North-Western Journal Of Zoology
2013, Volym: 9, nummer: 2, artikelnummer: 131603
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