A new publication on Sierra Birds (Birds of the Sierra Nevada: Their Natural History, Status, and Distribution 2013; University of California Press is among the first books to make extensive use of eBird data.
In writing species accounts of regularly-occurring Sierra birds, the authors explored eBird data for all migratory species to confirm typical arrival and departure dates from the region.
According to co-author Ed Pandolfino, "In addition to reviewing our personal experience and consulting with local experts and published accounts, we also checked data from eBird to see when significant numbers of each species arrived or departed from different parts of the Sierra."
Interestingly, they found that, while dates from eBird data were generally consistent with personal experience, they differed for many species from the best historical reference, David Gaines', Birds of Yosemite and the East Slope (1992, Artemisia Press).
For many insectivorous birds such as Olive-sided, Pacific Slope, and Ash-throated Flycatchers, Western Kingbird, Barn Swallow, Yellow, Nashville, and Wilson's Warblers, arrival dates appear to have advanced one to two weeks. That is, all these species seem to be arriving in good numbers in the Sierra earlier than they did just 30 years ago.
The authors also examined eBird data to confirm the presence of species at the edges of their ranges or to find areas where ranges had changed.
After confirming eBird observations with local experts, they were able to describe phenomena such as localized populations of California Towhees on the east of the Sierra Crest on the western edge of Owens Valley and the presence of small numbers of Verdin resident in desert canyons at the very southeastern tip of the Sierra.
More at: www.ebird.org
Book available at: http://www.ucpress.edu/book.php?isbn=9780520274945
Photo: Olive-sided Flycatcher, California, April. Photo by Brian L. Sullivan
