“Apparently when the crop is poor, the additional food that helpers provide to nestlings doesn’t make up for the extra resources those helpers are using,” said Walter Koenig, the study’s lead author.
“Whereas when the acorn crop is good, their help is enough to significantly increase both the survivorship of the other birds in the group and the number of young the group can fledge. At least in acorn woodpeckers, living together in a family only confers benefits when food is plentiful.”
The research appears in the American Naturalist.
University of Chicago Press Journals (2011, July 27). It takes a village, but only in times of plenty, acorn woodpeckers show. ScienceDaily. Retrieved July 31, 2011, from http://www.sciencedaily.com /releases/2011/07/110727164933.htm