By Matt Schickling
Wire Staff Writer
In the next few weeks, volunteers from all over the Western Hemisphere will be taking part in a literal wild goose chase.
For the 115th year, the National Audubon Society will hold the Christmas Bird Count from Dec. 14 to Jan. 5, and Silver Lake Nature Center in Bristol will be taking the reins for Lower Bucks County.
“Lots of people look at birds for a hobby and get personal enjoyment out of it, but you can turn that into scientifically important information,” Robert Mercer, director-naturalist at Silver Lake, said.
He’ll be leading volunteers in one of the designated regions on Sunday, Dec. 20. The area consists of a circle with a 7.5-mile radius centered on the Langhorne Post Office. It includes the areas of Bucks County south of Washington Crossing, Richboro and Trevose. As compiler, Mercer will be recording the census data brought in by volunteers from this region.
Last year in this area, Mercer tallied 97 species and 114,227 individual birds with 64 volunteers that broke up into 21 parties. Overall, counts took place in all 50 states, all Canadian provinces and over 100 circles through Latin America, the Caribbean and the Pacific Islands. Count circles totaled at 2,408, with 71,659 volunteers participating. Together, they counted more than 66 million individual birds comprising 2,403 species.
“When I started, it was hard to get people. It was a less-popular activity,” Mark Gallagher, an ecologist from Lower Makefield, said. He’s been volunteering for the Christmas Bird Count since 1978 and sees a progression in the popularity of bird watching.
Now, he said, a competitive spirit drives birders. Sites like the Cornell-based eBird, which keeps an online record of the birds a person sees and compares them with others in the area, foster this competition.
Mercer admitted that counting every bird would be nearly impossible, but this is the longest-running wildlife census on the planet, and the results have important implications when analyzing them year to year.
“There’s just no way to count every bird, but if you go to the same areas year after year, after time you get a trend. You get a feel for what’s in that area,” he said. “It creates an equalizing formula. Scientifically, the data is still valuable.”
Formulas are developed to look at the numbers as trends, which, because of the longevity of the census, can output accurate information.
“Some birds you see no trends at all, other birds you see very distinct trends,” Mercer said.
For example, Canada Geese, the long-necked gray, black and white birds that occupy the shorelines of the Delaware in Lower Bucks, weren’t seen in the area until 1950, when two were tallied in the census.
Now, they’re everywhere. In 2013, 11,862 were counted in this region, with the peak at around 27,000 in 1995.
“Looking at the raw numbers, that’s quite a change,” Mercer said.
Another interesting trend is the bald eagle. They were not seen in the area until 1980, when one was counted. There was not another sighting during the census until 1991, when one was seen again. Since, they’ve been seen every year, with the peak at 13 in 2005.
These numbers are encouraging to bird watchers, as the bald eagle was once on the U.S. government’s list of endangered species.
Locally, the numbers may seem fairly insignificant, but nationally, they contribute to a wealth of data that can help trace migratory patterns and the well-being of these birds.
“Put together with national data, it can really look at trends regarding the health and status of these birds across America,” Mercer said. “The scientists are going to look at national trends.”
Some of the national trends that have been identified in recent years are cardinals moving north and the American kestrel population plummeting because their habitat is disappearing.
“This is not just about counting birds,” Gary Langham, Audubon’s chief scientist, said. “Because birds are early indicators of environmental threats to the habitats we share, this is a vital survey of North America, and increasingly, the Western Hemisphere.”
People interested in volunteering locally should not just count birds in their backyards, as the data will likely be rejected. It’s best to contact Mercer directly so that they can be connected to other volunteers to more accurately count the territory. Others can visit the National Audubon Society website to find out when and where counts are taking place in their communities.
“I think it’s fun just looking at them at the very local level,” Mercer said. “We’re visiting key open-space areas that are least disturbed, where you have the highest concentration of birds.”
For more information on the Christmas Bird Count, visit www.audubon.org. To volunteer locally, contact Robert Mercer at 215–785–1177 or email [email protected].
