FOOD LIMITATION DURING BREEDING IN A HETEROGENEOUS LANDSCAPE

Abstract

Abstract 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 n...