Which chick gets fed first in a brood seems to depend more on the environment than a chick’s begging or its size. That’s what researchers report after reviewing data on 143 different bird species.
When food is plentiful and supplies are stable, birds will usually feed the chicks who beg the most and are in the poorest condition. However when times are tough and food is in short supply, birds choose to feed the largest chicks, regardless of begging by the others.
The authors believe this review will help resolve a long-standing question in ecology of whether parents respond to signals of need (begging) or to signals of quality (such as the physical size) when deciding which of their offspring to feed.
The review compiled available literature, including 306 studies.
Original research paper published in Nature on March 30, 2015.
Names and affiliations of selected authors