FUNDING
This work was supported by the Cornell Lab of Ornithology Athena Grant, the Andrew W. Mellon Student Research Grant, the American Ornithological Society Research Award, and the Cornell University EEB Paul P. Feeny Graduate Student Research Fund (all to N.R.H.) N.R.H. was also supported by the following fellowships: Charles Walcott Graduate Fellowship, Treman-Williams Graduate Fellowship, Edsall Ornithology Graduate Fellowship, and the Ivy Fellowship.