For those users not familiar with conventions of scientific citation, here's how it works. Any time a statement is made that is not based on the original research of the author, the person responsible who did make that particular discovery or offer that particular opinion must be credited, by means of a scientific citation. In some forms of scholarship, this is done with footnotes. Scientific publications, however, use a different convention, which is followed throughout this work. After the statement in the text, the name(s) of the author(s) and year of publication of the information are enclosed in parentheses. If the name(s) of the author(s) is mentioned in the text, then only the year of publication is enclosed in parentheses. The full reference is given in the "Literature Cited" section, which includes only references cited in the text, and is therefore not the same as a bibliography. Cited references are arranged alphabetically by author (s) and year of publication. When a publication has more than two authors, it is typically cited in the text as First Author "et al." All authors' names are given in the Literated Cited section. I follow the conventions of The Auk, flagship publication of the American Ornithologists' Union, except that I spell out the names of the scientific serials (journals and monograph series) in which articles are published, instead of using standard abbreviations.


American Ornithologists' Union. 1973. Thirty-second supplement to the American Ornithologists' Union Checklist of North American birds. Auk 90:411-413.

Beecher, M. D. 1988. Spectrographic analysis of animal vocalizations: implications of the "uncertainty principle." Bioacoustics 1:187-208.

Kaufman, K. 1990. A field guide to advanced birding. Houghton Mifflin Co., Boston, MA.

Kroodsma, D.E. 1984. Songs of the Alder Flycatcher (Empidonax alnorum) and Willow Flycatcher (Empidonax traillii) are innate. Auk 101:13-24.

Kroodsma, D. 2005. The singing life of birds. Boston, Houghton Mifflin.

Lowther, P. E. 1999. Alder Flycatcher (Empidonax alnorum). In The Birds of North America, No. 446 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Peterson, R.T. 1987. Those tricky Alder and Willow Flycatchers. Birding 19:14-16.

Sedgwick, J. A. 2000. Willow Flycatcher (Empidonax traillii). In The Birds of North America, No. 533 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Sedgwick, J.A. 2001. Geographic variation in the song of Willow Flycatchers: Differentiation between Empidonax traillii adastus and E. t. extimus. Auk 118:366-379.

Stein, R.C. 1958. The behavioral, ecological, and morphological characteristics of two populations of the Alder flycatcher Empidonax traillii (Audubon). N.Y. State Mus. Sci. Serv. Bull. No. 371.

Stein, R.C. 1963. Isolating mechanisms between populations of Traill's Flycatchers. Proc. Am. Phil. Soc. 107: 21-50.