Christmas Bird Count: Is that Two Turtle Doves or One?
Barred owl photo by Glenn Tepke for Audubon Society
It's time for the 110th Christmas Bird Count, the annual holiday tradition when tens of thousands of volunteers, from Alaska to Antarctica, look and listen for birds, counting populations for researchers. The National Audubon Society organizes the CBC, tracking species from mid-December to January 5 for the season's yearly bird census. You can even do it from a feeder. So where are the six geese a-flyin'?
Volunteer citizen scientist counting birds. Photo by Amy Kovach courtesy of Audubon Society
Participants throughout the US, Canada and 19 other countries in the Western Hemisphere count birds over a 24-hour period along a specified route in a 15-mile (24-km) circle. Armed with binoculars, bird guides and checklists, the volunteer bird watchers, birders and families join scientists, identifying and recording different species to be analyzed for changes. Some watch feeders at home in specific designated areas while the majority observes in the field, compiling data on thousands of birds from a partridge in a pear tree to four calling birds.
Vanishing Purple Finch photo by Ashok Khosla for Audubon Society.
It all began on Christmas Day in 1900, when an ornithologist at the American Museum of Natural History, Frank Chapman, was concerned about declining bird populations from bird hunting. So he organized an alternative bird "hunt," in New York City's Central Park and Princeton, New Jersey. This Christmas Bird Count was so successful it solved the problem (back then). The Audubon Society continued the event when it was formed in 1905 and it's grown bigger each year. Unfortunately, the birds haven't of late.
Three French Hens...Two...One...
Analyses of data collected by citizen scientists from the past 40 years of Audubon's Christmas Bird Count (CBC) reveal a troubling 58 percent of the 305 species on the continent have shifted significantly north in winter since 1966, some by hundreds of miles. Movement was detected among species of every type, including more than 70 percent of highly adaptable forest and feeder birds.
Research has contributed to the first State of the Birds Report in 2009 from the US Department of the Interior. The CBC analysis has revealed the impact of climate change on bird populations. With habitat destruction and warming temperatures, a majority of US birds have moved further north and inland in an attempt to adapt.
Boreal Chickadee headed north. Photo by Jeremy Yancey for Audubon Society
Purple Finch, Pine Siskin, and Boreal Chickadee have retreated dramatically north into the Canadian Boreal, moving their range between 279 to 433 miles. Red-breasted Merganser, Ring-necked Duck, and American Black Duck, normally found in the south, have taken advantage of warmer winter waters, shifting north by an estimated 182 to 317 miles. Grassland species, such as Eastern Meadowlark, Vesper Sparrow, and Burrowing Owl were actually unable to move because habitat areas disappeared. As a result, so may they.
Yellow-billed Magpie on the move. Photo by Ashok Khosla for Audubon Society
One third of the California native bird species will experience significant reductions in geographic ranges over the coming decades due to the negative impact of climate change, according to Audubon. The California Gnatcatcher could lose up to 56 percent of its range, the Chestnut-backed Chickadee range could diminish as much as 49 percent, and Yellow-billed Magpies, which live in the Central Valley and Coast, could lose as much as 75 percent of its range.
Sign Audubon's petition to lawmakers urging them to adopt mandatory measures that reduce greenhouse gas emissions, to switch to clean renewable energy, end dependence on oil, and other measures in order to ensure the health and survival of bird populations.
Is that seven swans a-swimming--or six? Check to see if there's still a bird count near you.
More on bird counting:
The Case of the Vanishing Birds
The Big Deal With Citizen Science
Bird Watching: Not Just for Dorks Anymore