A Bird Count for History

Great Backyard Bird Count sets a new record

By Miyoko Chu

Hooded Merganser counts were up compared with the past two years.

James Hendrickson, GBBC participant

Great Backyard Bird Count participants made history this year, breaking records for the number of birds and checklists reported. Participants counted 11,082,048 birds of 616 species during the four-day event, February 16–19, 2007. They submitted 81,193 checklists online, surpassing by far the previous record of 61,049.

"Literally, there has never been a more detailed snapshot of a continental bird-distribution profile in history," said John Fitzpatrick, director of the Cornell Lab of Ornithology. "This is an exciting, timeless project and this year it achieved real scale. Imagine ornithologists and ecologists 250 years from now comparing these data with their own!"

Participants documented the locations of diverse birds across the United States and Canada, including the endangered Io, or Hawaiian Hawk on the island of Hawaii, Violet-crowned Hummingbird in southern Arizona, Rhinoceros Auklet in Sitka, Alaska, and Spruce Grouse in Yellowknife, Northwest Territories.

For the first time ever, the American Robin was the most numerous bird reported in the GBBC (see accompanying article). Rarities included the first state GBBC records for Virginia's Warbler in West Virginia and Scott's Oriole in Pennsylvania. Participants also recorded three species new to the GBBC this year: Lesser Prairie-Chicken (Oklahoma), Falcated Duck (Oregon), and Pink-footed Goose (Rhode Island).

Anyone who visits the web site at www.birdcount.org can explore dynamic maps showing how bird distribution and abundance have changed during 10 years of the GBBC.

Common Raven by C. R. Tucker, GBBC participant

This year's GBBC showed a drop in reports of Northern Pintails, elegant ducks that winter along the coast and much of the southern interior United States. When adjusted for differences in the numbers of checklists, reported numbers were down by 50–60 percent compared with the past two years. This does not mean that pintail populations have declined by that amount; GBBC tallies of flocking birds such as pintails can vary tremendously depending on which flocks were counted. However, data from the Christmas Bird Count and Breeding Bird Survey indicate that the species is in significant decline, perhaps because of agricultural activities on the prairie nesting grounds, according to the National Audubon Society's Waterbird Conservation program.

In contrast, GBBC tallies of Hooded Mergansers were up by 14–33 percent compared with the past two years, when adjusted for the number of checklists. This is good news since Hooded Mergansers are one of North America's least numerous ducks. Hooded Mergansers nest in tree cavities in forested wetlands and have a broad winter range, with GBBC reports from 53 states and provinces this year. According to The Birds of North America Online, Hooded Mergansers have suffered historic declines because of deforestation and hunting, although populations now seem to be stable and possibly increasing in some areas.

In addition to helping keep tabs on the abundance of birds, the GBBC captures the year-to-year movements of wintering birds because of weather, food supply, and other factors. These maps capture the dynamic nature of bird distribution and movements in a way that no static map ever could.

"Traditional range maps can take years to make, and they usually present "averages" over multiple years that often don't reflect where birds are in any given year," said Ken Rosenberg, the Lab of Ornithology's director of Conservation Science. "With the GBBC, we can get maps in just a few days each year, allowing us to track the dynamic changes in winter bird populations through time, especially for common species. It's an extremely powerful way of mapping winter ranges."

This year's count documented a delayed Sandhill Crane migration compared with 2006 and complex movements of irruptive finches such as Common Redpolls. Participants reported significant numbers in the West, but not the East, a departure from the early years of the GBBC, which captured southward movements across the continent every other year. For more details of these and other highlights from around the continent, please visit www.birdcount.org.

For permission to reprint all or part of this article, please contact Laura Erickson, editor, Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY, 14850. Phone: (607) 254-1114. email: lle24@cornell.edu