Great Backyard Bird Count Highlights
March 23, 2011
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| Female Evening Grosbeak by GBBC participant Carrie, Maine |
Overview
Participants submitted more than 92,000 checklists to the GBBC this
year--the third year in a row that checklists topped 90,000. New
checklist records were set in 11 states and in 7 out of 13 Canadian
provinces and territories, resulting in a new overall checklist record
for Canada. Altogether, participants identified 596 species and 11.4
million bird observations. What follows is a look at some of the trends
and more notable findings of this year’s GBBC,
including:
- Increased reports of Evening Grosbeaks
- Winter finches move southward
- Are American Crows on the rebound?
- Eurasian Collared-Dove makes it to Alaska
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| European Starlings by GBBC participant Nat Winston III, Tennessee |
Number Crunch
The most numerous bird counted in the 2011 GBBC was the European Starling—a species that was entirely absent from North America before the late 19th century. One hundred birds were introduced in New York's Central Park in 1890 and 1891. According to The Birds of North America Online, the descendants of these few birds now total more than 200 million and are distributed across the entire continent.
The American Robin was the second most numerous species reported this year with more than 800,000 reported from Florida—for the third year in a row, the site of a massive roost near St. Petersburg. Overall, GBBC participants made 1,044,346 observations of robins this year.
Rarities
As usual, there were some surprises during the GBBC. Participants reported two new species that have never appeared on GBBC checklists before. These include a Brown Shrike in McKinleyville, California—an Asian species far from home. Over on the East Coast, a participant reported a Common Chaffinch, another first for the GBBC. This bird was seen in Placentia, Newfoundland and Labrador. It is a Eurasian species that occasionally turns up in the Canadian Maritimes and the northeastern United States.
Other rarities this year include a Common Snipe in Newfoundland and Labrador—the Eurasian relative of the Wilson’s Snipe.
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| Hoary Redpoll by GBBC participant Harry Mueller, Manitoba (2009) |
Tammie Hache in Manitouwadge, Ontario, reported having an
exceptional season for Hoary Redpolls. She counted 20 in her backyard
on Friday morning of the GBBC during a big snowstorm!
Hoary and Common redpolls are "irruptive" species. That means they
occasionally and unpredictably move farther south from their usual
wintering ranges in Canada. These movements are linked to the size
of the seed crops. When there are fewer seeds up north the irruptive
species move southward to find what they need.
In Alaska, Victoria Winne observed a Brambling visiting her feeder
before, during, and after the GBBC—the only one reported for all of
North America. This species typically lives in the forests of Northern
Europe and in Asia, but does occasionally stray into Alaska during
migration. It has been reported a handful of times in the past during
the GBBC: Alaska in 2008, British Columbia in 2001, 2004, and 2006, and
as far south as Oregon in 2002.
Another rarity during winter in North America is the Swainson’s Thrush. It’s a common enough songbird in the summertime, when its fluting song can be heard across much of the continent—but in winter most of them are in Central and South America. A participant in Winston-Salem, North Carolina, reported a Swainson’s Thrush to the GBBC this year. Only a handful of widely scattered reports of this species have been made to the GBBC during its 14 years, the most recent in 2005.
And John Lester of Myrtle Beach, South Carolina, was thrilled to receive confirmation of his sighting of a Ross’s Goose. The bird was mingling with a flock of Canada Geese and Lester thought at first the stranger might be a Snow Goose. When GBBC data reviewer Dennis Forsythe reviewed Lester's photos he was able to identify it as a Ross's Goose, the Snow Goose's smaller, rarer lookalike. It’s also the first time a Ross’s Goose has been reported in South Carolina for the GBBC.
Movement Patterns
In addition to the redpolls mentioned above, other irruptive species
such as Pine Siskins and Red-breasted Nuthatches were on the move too.
Their movements were more extensive than last year, but nothing like
the major movements seen in 2009. The extent and magnitude of bird
movements were remarkably similar to those in 2008, with modest numbers
of Pine Siskins as far as the Southeastern Coastal Plain and fair
numbers of redpolls into the Northeast. Pine Siskins were widespread
and common in much of the West.
Let’s take a closer look at the Pine Siskin. This year, participant
reported 66,471 Pine Siskins, up 65% from last year when adjusted for
the number of checklists. But 2009 was an even bigger year, with four
times more siskins reported than this year. The animated map below
shows the fluctuations in Pine Siskins reports during the GBBC from
2000 through 2011.
This pattern of irruption is also evident in reports of White-winged
Crossbills. Participants reported 24% more crossbills this year
compared with last year, when adjusted for the number of checklists.
However, the number was nearly five times higher in 2009 than this
year.
White-winged Crossbills have upper and lower mandibles that twist in opposite directions. As odd as that looks, it’s just what the birds need to pry the seeds out of the spruce cones that make up the bulk of their diet. Watch this video to see how they go about using this specially adapted bill to get at the good stuff.
Evening Grosbeak
Although the colorful and gregarious Evening Grosbeak has been declining in overall numbers over the past 20 years, participants reported a surprising increase in the number of grosbeaks this year. The total number of observations for this species is the highest it has ever been during the GBBC, an increase that isn't simply attributable to greater GBBC participation. A closer look finds this upturn especially marked in the northwestern U.S. and in Canada. However, the Evening Grosbeak is also an irruptive species and this increase in reports may simply reflect that. We’ll keep monitoring their numbers in future counts to see whether this is indicative of a long-term trend.
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| American Crow by GBBC participant Gary Botello, Arizona |
Crows on the Rebound?
Over the years, we’ve kept a sharp eye on American Crow numbers during the GBBC. The population took a hard hit when the West Nile virus first found its way into North America in 1999. In the early years of the GBBC, American Crows were always the fourth or fifth most numerous species reported. But after the virus worked its way across the continent, crow numbers fell and were reflected in the GBBC. From 2003 onward, the American Crow never placed higher than the ninth or tenth most numerous species. 2011 marked a change. For the first time in eight years crows have moved up the list and are now at number seven among the most numerous species. Monitoring the crow count in the years ahead will tell us whether this is a one-year fluctuation or evidence of a true recovery for this species from the devastation of West Nile virus.
Species on the March
We pay special attention each year to reports of the Eurasian Collared-Dove, an invasive species that was introduced to North America via Florida in the 1980s. In 2011 the species continued its march across the continent, and this year marked the first GBBC report of Eurasian-Collared Dove in Alaska. That is the bird’s most northerly reach to date, having moved into western Canada’s provinces in recent years on its way north. In Canada, the Eurasian Collared-Dove was reported on 65 checklists this year compared to just 19 last year. The dove has expanded its range from 8 states in 1999 to 40 states and provinces in 2011. It's interesting that the species has made it all the way to Alaska but has yet to be reported anywhere in the Northeast.
Explore
These are just a few of the trends we've seen in a preliminary look at 2011 GBBC data. Although in-depth studies are necessary to fully evaluate any trends in bird distribution found during the GBBC, and to document their causes, these preliminary results offer a tantalizing glimpse of what we can learn when tens of thousands of people get together to watch birds and report their sightings.
Do some data exploring on your own! Are you curious about how many others in your state or province reported a particular species? Are the overall numbers of Tree Swallows up or down this year? How have your own observations fluctuated over time? Go to our website and click "Explore the Results" to start browsing through the data from all 14 years of the GBBC. You can always find your own reports by clicking on “Explore the Results,” “Detailed Reports,” and “My Observations.” You just need to enter the same email address you used to file your checklists.
If you enjoyed the GBBC and can't wait for next year's count, remember that you can participate in important data gathering any day of the year by using the free eBird online checklist program.
And save the dates: the next GBBC is February 17-20, 2012!
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| Fourth graders at Dryden Elementary School in New York participate in their first GBBC. Photo by Erin Peppel |
