Lack of fine-tuned egg rejection adjustment in barn swallows with variable brood parasite exposure
Description
We tested whether variation in co-occurrence between the host and its rare brood parasite, the common cuckoo Cuculus canorus (i.e., high level of co-occurrence in reed habitats, low in town habitats) at the metapopulation level predicts patterns of antiparasitic egg rejection behaviors in barn swallows in response to different types of model and natural eggs. The data include point count data of barn swallows and cuckoos, egg reflectance data for the experimental eggs and barn swallow eggs and egg rejection rate of the barn swallows in two habitats. We found lack of fine-tuned increase of egg rejection rate in the reed-breeding population of barn swallows as a response to the increased perceived cuckoo parasitism pressure in the reed habitat.