@article {Weeks610329, author = {Brian C. Weeks and David E. Willard and Aspen A. Ellis and Max L. Witynski and Mary Hennen and Benjamin M. Winger}, title = {Shared morphological consequences of global warming in North American migratory birds}, elocation-id = {610329}, year = {2019}, doi = {10.1101/610329}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Increasing temperatures associated with climate change are predicted to cause reductions in body size, a key determinant of animal physiology and ecology. Using a four-decade specimen series of 70,716 individuals of 52 North American migratory bird species, we demonstrate that increasing annual summer temperature over the 40-year period drove consistent reductions in body size across these diverse taxa. Concurrently, wing length {\textendash} which impacts nearly all aspects of avian ecology and behavior {\textendash} has consistently increased across taxa. Our findings suggest that warming-induced body size reduction is a general response to climate change, and reveal a similarly consistent shift in an ecologically-important dimension of body shape. We hypothesize that increasing wing length represents a compensatory adaptation to maintain migration as reductions in body size have increased the metabolic cost of flight. An improved understanding of warming-induced morphological changes, and their limits, are important for predicting biotic responses to global change.}, URL = {https://www.biorxiv.org/content/early/2019/04/18/610329}, eprint = {https://www.biorxiv.org/content/early/2019/04/18/610329.full.pdf}, journal = {bioRxiv} }