Christmas Bird Count data is vital to scientific research

In Changing times, The Christmas Bird Count is More Important Than Ever

Audubon Acclaims Guide Carlos Sanchez’s New Homestead Circle as among the most “ornithologically significant” in Florida

Record species counts, four new U.S. birds and enthusiastic participation were among the pleasant surprises in the 2020-2021 Christmas Bird Count data Audubon released this week, especially since last year’s count was nearly canceled because of COVID-19.

“Even with the adjustments needed to do a COVID-safe Christmas Bird Count, pretty much across the hemisphere compilers and participants felt that both the numbers of birds tallied and the array of species found were as high as, if not a bit higher than, average,” Geoff LeBaron, director of the Christmas Bird Count wrote in Audubon’s summary of the 121st annual bird census.

Carlos Sanchez’s Homestead, FL Christmas Bird Count Circle drew praise from Audubon this year, though his recorders were spread thinner than this FL tour group!

Despite having 10 percent fewer counts and counters, the 121st Christmas Bird Count turned up 2 million more birds than the previous year’s 42 million. Though fewer in number, volunteers logged more overall hours than in any of the past 10 years.

Generally warmer and more favorable weather attracted and kept volunteers in the field, Audubon wrote in its summary, and because of COVID, birding parties tended to be smaller and more likely on foot than in cars, maximizing opportunities to spot birds.

New species are always a highlight in the data, and it won’t surprise savvy birders to learn the four species novel to the US were found near borders: three in Florida and one in Alaska.

  • Christmas Bird Count data sometimes turns up new species, like this Siberian Accentor, found near Homer, AL
  • Christmas Bird Count data sometimes turns up new species like the Red-Legged Thrush
  • Christmas Bird Count data frequently finds new species, like this Cuban Pewee
  • Christmas Bird Count data is vital to studying populations like this black-faced Grassquit

“The Cuban Pewee and Black-faced Grassquit at Lower Keys – Key Deer N.W.R. in Florida, the Red-legged Thrush at Key West in Florida, and the Siberian Accentor at Homer in Alaska were new species,” Audubon wrote on its annual tally announcement this week.

Christmas Bird Count data is critical for scientists grappling with how bird populations respond to environmental changes, noting where species are moving to or from. Longer-lingering warblers and dramatically more widespread distribution of late hummingbirds were noted in last year’s data, for example.

Conducted every year between Dec. 14 and Jan. 5 by volunteers throughout the Americas, Audubon’s Christmas Bird Count has been producing critical scientific data since 1890, when ornithologist Frank M. Chapman proposed a bird census to replace the traditional Christmas “side hunt,” a competition for which party of hunters could indiscriminately shoot and kill the most birds and animals.

From a 1905 book “Birds that Hunt and are Hunted,” courtesy of Library of Congress.

Though 250 Christmas Bird Count circles opted out of last year’s count, most citing the pandemic, 43 new birding areas were inaugurated, including one organized by guide Carlos Sanchez in Homestead, FL. Based on inaugural data released this week, Florida Audubon wrote, the southwestern Miami-Dade count “should become one of the most ornithologically significant CBCs in Florida.”

Bridging a gap on the map between the Everglades CBC and the one in Kendall, Homestead “has demonstrated it can produce high counts of individuals with some of the best in the country,” Audubon wrote on its national CBC summaries page. 

“It features oddball wintering populations of Swainson’s Hawk, Lesser Nighthawk, Brown-crested Flycatcher, Western Kingbird, and other western species,” Carlos wrote to tell us about his team’s impressive results.

“We are generating these numbers with a rather skeletal crew of 30-35 birders. I believe there are statistically significant wintering populations of many warbler species, some of which are not even being shown on field guide maps right now.”

Christmas Bird Count data is vital to studying bird populations like the one of Homestead, FL
Graphic by Carrie Miller

In fact, a widespread northern movement of birds like White Ibis from the Everglades into Florida city suburbs is the current cover story of Audubon Magazine.

Among the trends the 2020-2021 Christmas Bird Count data continued to support were two related to the milder temperatures: more and more widespread reporting of both hummingbirds and warblers. 

Once counted only by Christmas Bird Count circles in the Gulf Coast and in Florida, the Ruby-throated Hummingbird “is becoming regular on CBCs up the Atlantic Coast as far as the Outer Banks, and this past season was seen on several counts as far north as Virginia and Maryland,” Audubon wrote.

  • Christmas Bird Count data show lingering warblers, like this Yelllow Warbler
  • Christmas Bird Count data show lingering warblers, like this Prothonatary Warbler
  • Christmas Bird Count data are showing lingering and northward movement of Ruby-throated Hummingbirds.

American Redstart, Blue-winged, Chestnut-sided, Grace’s, Lucy’s, MacGillivray’s, Prothonotary, Tennessee, Worm-eating, and Yellow warblers are now lingering, when in years past they would have vacated North America by the time the count rolled around.

On the less-abundant side of the coin, data showed continued declines in Ruffed Grouse populations.

“Given that in some regions wildlife agencies manage habitat to benefit Ruffed Grouse it is something of a mystery why the decline continues, but this species is naturally cyclical in its populations so hopefully we are at the bottom of the ebb these seasons,” wrote LeBaron, the CBC director.

If you haven’t already, join in a Christmas Bird Count, and sign up here at the Audubon website. Happy “hunting”!

Can we count on you to share your Christmas Bird Count photos and videos?

Christmas Bird Counts are sometimes estimates!
Birding Bosque del Apache, NM in Dec. 2021. Photo Credit: Bryan Calk

We would love it if you would share with us photos or videos from your local circle’s participation in the Christmas Bird Count this year! By email, send them to: or tag us in your Instagram posts with #naturalistjourneys or add us to your Facebook posts using @naturalistjourneysllc. Thank you!

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