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Age and performance at fledging are a cause and consequence of juvenile mortality between life stages

June 20, 2018

Should they stay or should they leave? The age at which young transition between life stages, such as living in a nest versus leaving it, differs among species and the reasons why are unclear. We show that offspring of songbird species that leave the nest at a younger age have less developed wings that cause poorer flight performance and greater mortality after fledging. Experimentally delayed fledging verified that older age and better developed wings provide benefits of reduced juvenile mortality. Young are differentially constrained in the age that they can stay in the nest and enjoy these fitness benefits because of differences among species in opposing predation costs while in the nest. This tension between mortality in versus outside of the nest influences offspring traits and performance and creates an unrecognized conflict between parents and offspring that determines the optimal age to fledge.

Publication Year 2018
Title Age and performance at fledging are a cause and consequence of juvenile mortality between life stages
DOI 10.1126/sciadv.aar1988
Authors Thomas E. Martin, Bret Tobalske, Margaret M. Riordan, Samuel B. Case, Kenneth P. Dial
Publication Type Article
Publication Subtype Journal Article
Series Title Science Advances
Index ID 70201108
Record Source USGS Publications Warehouse
USGS Organization Coop Res Unit Seattle