When are egg-rejection cues perceived? A test using thermochromic eggs in an avian brood parasite host.

When are egg-rejection cues perceived? A test using thermochromic eggs in an avian brood parasite host. Anim Cogn. 2019 Sep 12;: Authors: Hauber ME, Dainson M, Luro A, Louder AA, Hanley D Abstract At the core of recognition systems research are questions regarding how and when fitness-relevant decisions made. Studying egg-rejection behavior by hosts to reduce the costs of avian brood parasitism has become a productive model to assess cognitive algorithms underlying fitness-relevant decisions. Most of these studies focus on how cues and contexts affect hosts' behavioral responses to foreign eggs; however, the timing of when the cues are perceived for egg-rejection decisions is less understood. Here, we focused the responses of American robins Turdus migratorius to model eggs painted with a thermochromic paint. This technique modified an egg's color with predictably varying temperatures across incubation: at the onset of incubation, the thermochromic model egg was cold and perceptually similar to a static blue model egg (mimicking the robin's own blue-green egg color), but by the end of an incubation bout, it was warm and similar to a static beige egg (mimicking the ground color of the egg of the robin's brood parasite, the brown-headed cowbird Molothrus ater). Thermochromic eggs were rejected at statistically intermediate rates between those of the static blue (mostly accepted) and static beige (mostly rejected) model eggs. This impli...
Source: Animal Cognition - Category: Zoology Authors: Tags: Anim Cogn Source Type: research