
Henrik Smith
Professor

Food limitation during breeding in a heterogeneous landscape
Författare
Summary, in English
Breeding success in birds may be determined by the availability of food that parents can provide to growing nestlings. A standard method for testing the occurrence of food limitation is to provide supplemental food during different parts of the breeding period. If there is spatial variation in the strength of food limitation, the effect of such an experiment should also vary spatially. We investigated whether the strength of food limitation during nestling rearing in the European Starling (Sturnus vulgaris) was related to the management intensity of agricultural landscapes. We fed birds mealworms during the nestling period in landscapes with high or low local availability of pasture, the preferred foraging habitat. Both habitat and food supplementation affected growth and survival of nestlings; the effects of the food-supplementation experiment were generally stronger than those of habitat. Mortality mainly struck the last-hatched chick. Both habitat and food supplementation positively affected nestling growth, measured as nestling tarsus length. In addition, food supplementation positively affected feather growth and asymptotic mass. Contrary to expectation, no interactions existed between effects of habitat and food supplementation, which suggests that breeding success was limited by food availability in both landscapes. Potential reasons for this lack of effect are parental compensation and low statistical power. Also, breeding densities were higher in landscapes with more pastures, possibly equalizing the per-capita availability of food. Thus, our results demonstrate that reproductive success was limited by availability of food when local availability of preferred foraging habitat was either low or high, but fail to demonstrate spatial variation in the strength of food limitation.
Avdelning/ar
- Biologiska institutionen
- Biodiversitet
- Biodiversitet och bevarandevetenskap
Publiceringsår
2006
Språk
Engelska
Sidor
97-107
Publikation/Tidskrift/Serie
The Auk
Volym
123
Issue
1
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Oxford University Press
Ämne
- Ecology
Status
Published
Forskningsgrupp
- Biodiversity and Conservation Science
ISBN/ISSN/Övrigt
- ISSN: 0004-8038