climate
Ridgely, R. S. and J. A. Gwynne, Jr. 1989. A Guide to the Birds of Panama. 2nd edition. Princeton University Press, Princeton, USA.
Kearney, T.H., R.H. Peebles, and collaborators. 1951. Arizona flora. 2nd edition with Supplement (1960) by J.T. Howell, E. McClintock, and collaborators. Univ. California Press, Berkeley. 1085 pp.
Anders, A. and E. Post. 2006. Distribution-wide effects of climate on population densities of a declining migratory landbird. Journal of Animal Ecology 75:221-227.
Enscore, R.E., B.J. Biggerstaff, T.L. Brown, R.F. Fulgham, P.J. Reynolds, D.M. Engelthaler, C.E. Levy, R.R. Parmenter, J.A. Montenieri, J.E. Cheek, R.K. Grinnell, P.J. Ettestad, and K.L. Gage. 2002. Modeling relationships between climate and the frequency