Influence of riparian tree phenology on lower Colorado River spring-migrating birds [electronic resource] : implications of flower cueing / by Laura J. McGrath and Charles van Riper III ; in cooperation with the Northern Arizona University, Department of Biological Sciences.
Imprint
Reston, Va. : U.S. Dept. of the Interior, U.S. Geological Survey, [2005]
Mode of access: Internet from the USGS web site. Address as of 02/07/08: http://pubs.usgs.gov/of/2005/1140/of2005-1140.pdf; current access available via PURL.