Allopreening

Allopreening typically focuses on the head and neck — regions a bird cannot easily reach itself — targeting ectoparasites such as feather lice and mites. It is most frequent in permanently pair-bonded species and peaks before and during the breeding season. In colonial nesters like herons and cormorants, allopreening extends beyond mated pairs to neighbors, reducing parasite load across the colony. Some studies suggest that allopreening time correlates with pair-bond strength and reproductive success.