Central place foraging in the European bee-eater, Merops apiaster.

Tested whether variation in the size of prey fed by parent bee-eaters to nestlings could be explained by a model of central-place foraging. The model predicted that selectivity for large prey should increase with distance travelled by the parents from the nest to the feeding site. Most of the prey brought to the nest were odonates and hymenopterans. As predicted by the model, there was a decrease in the proportion of items brought to the nest that were small with increasing travel time. The model predicted a threshold for dropping small items from the nestling diet. Statistical estimation of a threshold from the observed data by probit analysis showed that the predicted threshold was within 2 standard errors of the observed. Estimates of relative prey abundance and observations of parents collecting food for themselves showed that differential availability of small prey at different distances from the nest could not account for the size-distance relationship.-from Authors