Results Flood in to the Great Backyard Bird Count

Participants document ebb and flow of birdlife across the continent

By Paul Green, Chris Wood, and Brian Sullivan

During the 2005 Great Backyard Bird Count (GBBC), tens of thousands of people had a good time counting birds, provided some fascinating information, and broke a few records. On February 18–21, birders across North America reported more than 6.5 million birds, shattering the previous record of 4.8 million set in 2002. Participants submitted nearly 52,000 checklists, up 22 percent from last year, and tallied 613 bird species, surpassing the previous record of 567.

The GBBC recorded birds in all 50 states and all but one Canadian province, capturing the tremendous geographic variation in birds across the continent, from the 10 species reported in the Northwest Territories to the 377 species reported from Texas. Texas produced several Mexican birds rarely seen north of the border—Green-breasted Mango, Crimson-collared Grosbeak, and Roadside Hawk.

Calliope Hummingbird, Baton Rouge, Louisiana.
photo by GBBC participant Dennis Demcheck

Fourteen hummer species

Not everyone associates mid-February with hummingbirds, but the four-day count turned up 14 hummingbird species, including Calliope in Louisiana, Broad-billed in Texas, and Costa’s in Oregon. Continentwide, more Rufous Hummingbirds were reported than during any other count in the eight-year history of the GBBC.

Red-bellied Woodpeckers advance in the north

In recent years, GBBC citizen scientists have documented a dramatic expansion in the range of Red-bellied Woodpeckers. In New Hampshire, for example, birders reported just a few Red-bellied Woodpeckers each year between 1987 and 1995. Between 1998 and 2005, there was a 13-fold increase in the proportion of checklists reporting the birds and a 15-fold increase in the number of birds reported. In 2005, both the proportion of checklists reporting the species and the number of birds doubled over the previous year. Similar patterns emerge from New York, Michigan, and Ontario. Participants also reported red-bellies from North Dakota, Maine, New Brunswick, and, for the first time, Nova Scotia. The expansion of this opportunistic species could be related to maturation of northeastern forests and an increase in the annual growing season related to warming winter temperatures. GBBC results highlight the need for further research.

Westward Blue Jays

Blue Jays were recorded in every state this year except California, Nevada, Arizona, and Alaska, and every province or territory except for Yukon, Northwest Territories, and Nunavut. For historical perspective, consider that Blue Jays were not recorded in Colorado until 1905 and were still uncommon in the 1950s. They have gradually spread westward across the Great Plains in response to changes in habitat. Expansion increased dramatically in the West during the 1970s. This year’s GBBC (and sightings during the fall and winter) indicate a real western invasion. The last such invasions were during 1990–1991 and 1976–1977. Will GBBC data show another invasion 14 years from now?

Great Gray Owl, Ile Bizard, Montreal, Quebec.
photo by GBBC participant Peter Leupold

Unprecedented numbers of Great Gray Owls

Participants documented an unprecedented southward movement of Great Gray Owls, with 574 reported, dramatically higher than the previous high of 45 in 2001. The owls were also found farther south this year, in Minnesota and Wisconsin, as well as in Alberta, Ontario, Quebec, Saskatchewan, and Manitoba. Great Gray Owls feed mainly on field voles that tunnel beneath the snow and remain active throughout the winter. The owls have come south looking for food this winter, providing a real spectacle as they listen for sounds from beneath the snow, then “snow dive” for their prey in open fields.

Bohemian Waxwings

We also saw the largest movement of Bohemian Waxwings into the Southern Rockies in eight years of the GBBC. Participants reported 759 bohemians in Colorado, 121 in Utah, 136 in Wyoming, and 15 in the Nebraska panhandle. Observers in Oregon recorded nearly 500 Bohemian Waxwings—the first time the species has been reported from the Beaver State during the GBBC. The greatest numbers were found in Alberta, Saskatchewan, and Montana, with totals this year of more than 2,000 Bohemian Waxwings in each.

Common Redpolls make a surprise appearance

Usually, redpolls come southward every other year, and 2005 was supposed to be an “off year.” Instead, they made an unexpected appearance: 50,454 Common Redpolls were reported during this year’s GBBC, many of them in the Lower 48. When adjusted for annual variation in the number of checklists, these numbers were only 4 percent lower than during last year’s irruption. The number of redpolls reported in 2005 was 17 times higher than in 2003, a typical non-irruption year.

More to explore

We’ve barely scratched the surface with the GBBC results in this report. If you’d like to learn more, you can read a more detailed article, visit an online photo gallery, and explore results on your own at www.birdsource.org/gbbc. We thank everyone who participated in the GBBC this year. Please join us again February 17–30, 2006. If you’d like to contribute your bird sightings year-round, we encourage you to enter your data into eBird at www.ebird.org.

Paul Green is Audubon’s director of citizen science. Chris Wood and Brian Sullivan are eBird project leaders.

For permission to reprint all or part of this article, please contact Miyoko Chu, editor, Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY, 14850. Phone: (607) 254-2451. email: mcc37@cornell.edu