1 Department of Wildlife Ecology and Biodiversity, National Environmental Research Institute, Aarhus University, Aarhus University2 Department of Bioscience - Wildlife Ecology, Department of Bioscience, Science and Technology, Aarhus University3 Zoological Museum, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark4 Animal Behaviour Group, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark5 National Environmental Research Institute, University of Aarhus, Dept. of Wildlife Ecology and Biodiversity, Grenaavej 14, 8410 Rønde, Denmark6 Center for Macroecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark7 Department of Bioscience - Wildlife Ecology, Department of Bioscience, Science and Technology, Aarhus University
Knowledge of a species' spatial behaviour is essential for understanding its behavioural ecology and a prerequisite to planning of conservation strategies. The little owl has shown a substantial decline in North-western Europe and is on the road of extinction in Denmark. To quantify relevant aspects of spatial behaviour in the last remaining Danish population, we followed 27 radio-tagged owls representing 14 territories during a period of 2 years. Mated owls were resident at nesting sites year-round with half of all nocturnal locations found within 125 m. Nightly distance from roosts peaked in January (`x: 95%CI = 249: 195-319 m) and dipped in May (89: 66-121 m). Distance from roosts varied non-linearly with temperature with the longest distances found at 6°C. Home range size varied with more than a 10-fold difference between pairs, pairs with neighbours maintaining 2-3 times larger ranges than isolated pairs, independent of habitat composition. Mean home range size of 14 pairs was 41 (95%CI: 27-64) and 2.6 (1.5-4.5) ha for 90% and 50% minimum convex polygons. Males and females behaved similarly, except in the breeding season where females foraged closer to the nest. Mates overlapped completely in activity distributions and were located closer to each other than expected by chance, suggesting permanent pair-bond. Inter-mate distances were not shorter prior to egg laying compared to the rest of the year, indicating little male investment in mate guarding. No mates left their partner, but widowed birds left their territory within 6-12 months if unable to attract a new mate.
Journal of Ornithology, 2009, Vol 150, Issue 3, p. 537-548
Home range – Mate association – Residency – Telemetry – Territory fidelity