Nom du corpus

Corpus Systématique Animale

Titre du document

Dietary shifts, niche relationships and reproductive output of coexisting Kestrels and Long-eared Owls

Lien vers le document
Éditeur
Springer (journals)
Langue(s) du document
Anglais
Type de document
Research-article
Mots-clés d'auteur
  • Diet breadth
  • Overlap
  • Competition
  • Kestrel
  • Long-eared Owl
Nom du fichier dans la ressource
Oiseaux_v2b_00656
Auteur(s)
  • E. Korpimäki
Affiliation(s)
  • Department of Zoology, University of Oulu, Linnanmaa, SF-90570, Oulu, Finland
Résumé

Food samples of breeding Kestrels (Falco tinnunculus) and Long-eared Owls (Asio otus) were collected in the peak and low phase of their preferred prey (Microtus voles) in western Finland. Diets of pairs that bred as neighbours (?1 km) with interspecifics were compared with those of non-neighbours. In both species, neighbouring pairs fed less on Microtus voles and more on alternative prey than did non-neighbours. Competition theory predicts that diet overlap should be lower during prey shortage and that diet similarity should be especially reduced in neighbouring pairs. Observations were consistent with expectations: diet similarity was lower in the low vole years and neighbouring pairs showed less diet overlap that non-neighbours. Differences in habitat composition and prey availability at the sample sites should not confuse the results. In addition to the high diet similarity, hunting habitats and nest sites of the species overlapped almost completely; they only showed clear temporal segregation in hunting. Probably because of food competition, the neighbouring pairs of both species produced significantly fewer young than the non-neighbours. These results contrast with the view that the diet composition and dietary shift of rodent-feeding predatory birds can be interpreted in terms of simple opportunistic foraging. In the breeding season, interspecific competition for food seems to be an important factor that affects the niches of these species, especially in northern areas, where the seasonal low phase of voles in spring and the number of alternative prey are lower than in more southern areas.

Catégories Science-Metrix
  • 1 - natural sciences
  • 2 - biology
  • 3 - ecology
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Ecology, Evolution, Behavior and Systematics
Catégories WoS
  • 1 - science ; 2 - ecology
Identifiant ISTEX
5D3882CB7CC109CB76B5254E4B8CA22E93D3E312
Revue

Oecologia

Année de publication
1987
Présence de XML structuré
Non
Version PDF
1.3
Score qualité du texte
9.928
Sous-corpus
  • Oiseaux
Type de publication
Journal
ark:/67375/1BB-14XG90HN-H
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