Recent changes in the Earth's climate have been linked to changes in phenology, geographic distributions, and morphology of species, and warming temperatures associated with climate change have been predicted to result in decreases in avian body sizes. We examined changes in wing length and fat-free mass of 34,844 fall migrants from 31 neotropical migratory species captured at Patuxent Wildlife Research Center in Maryland between 1980 and 2012. Body size changes varied across species, but wing length and fat-free mass increased significantly over time in the pooled sample of all species. Magnitudes of change were small and similar to other studies, with mean wing length increasing 0.55% and mean fat-free mass increasing 1.30% across all species. General morphological changes at our site differed from those at a banding station located 235 km away. Across species, changes in wing length were weakly correlated between stations, and changes in fat-free mass were uncorrelated. Populations of some species showed opposite morphological changes, demonstrating that morphological changes can vary regionally. Over short time scales, factors other than climate might drive observed changes in body size of neotropical migrants, and alternative hypotheses for body size changes should be considered.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 24 • No. 1