Cowbird cognition: Examinations of the mental skills of a brood parasite

Abstract

Abstract Modern research in animal cognition considers cognitive skills to be modular processes evolved in response to species' specific ecological demands. Female brown-headed cowbirds (Molothrus ater) like other brood parasites experience a distinct cognitive challenge borne of their breeding biology; they must locate and select viable nests for their offspring. Here I review the information processing capabilities female cowbirds display that afford them the ability to parasitize hosts effectively. I manipulate artificial host eggs in nests and measure female cowbirds' prospecting and laying patterns while they live and breed in large outdoor aviaries. These experiments have revealed that cowbirds track a variety of types of information acquired during prospecting that permits them to evaluate nests, time parasitism effectively, and to copy the nest selection decisions of other females. Recent work has extended these findings to examine individual differences in cognitive skills among female cowbirds, and how these skills generalize to different problem-solving tasks and contexts. The cowbird system serves as an effective system to investigate the mechanisms and function of cognition using an ecologically relevant task directly linked to fitness.