Mission: Great Backyard Bird Count
by Sonia Linebaugh
We are the eyes and ears of Planet Earth
Think of it as being part of a space probe team. The space to be explored is right in your own back yard. The specialized tools are your eyes, binoculars if you’ve got them and a list of common birds. The occasion is the annual Great Backyard Bird Count.
Our mission is to help track bird population generally, but this year in particular our data will help scientists study the impact of cold and snow on bird migration.
Our method is this: On four days — February 14, 15, 16 and 17 — spend at least 15 minutes counting birds out your window, on your daily walk, from your boat or office. Each day, log on to www.birdsource.org/gbbc/results.htm to report your results to headquarters, a four-person staff at Cornell Lab of Ornithology. Record only the largest group of each kind of bird sighted in a single day to avoid counting the same bird over and over.
If you wonder why you should sign up for the mission, consider this:
We are the eyes and ears of Planet Earth. We are the discoverers and the explorers. We are uniquely qualified for the job. When you spend even a few daylight minutes near a window or outdoors, birds come into view or sound their calls.
Mourning doves and starlings queue up on telephone lines. Vees of geese honk their way across pink morning and red twilight skies. Gulls squawk on beach front and parking lots. Vultures prowl the roadsides.
Birds are everywhere. In the fields and on the shores of Bay, rivers and creeks, in the green spaces and treelined streets of Annapolis. On the waterfront at Inner Harbor and on the sidewalks of Glen Burnie. Birds are the most common and familiar critters in the whole world.
When is the last time you saw a bird? Was it this morning or yesterday afternoon?
Snakes, opossums, raccoons, deer, skunks and squirrels also abound in much of Anne Arundel County. It’s been two weeks since I saw a deer. I can’t remember if I saw any snakes last summer. Though I’ve smelled dead skunks on the roads in summer, I’ve never seen a skunk in the wild. Groundhogs and opossums poke heads out in fine weather. Once I spotted a raccoon in my compost pile. Jittery squirrels rank second to birds in familiarity but not in number.
Birds are so common that it seems a waste of time to bother counting them. They move fast, and they are hard to see. Sometimes they are just silhouettes against the sky. Or they’re far out on the water. Or they’re flitting about in the trees. And sparrows? They all look alike. Count them? No way.
Counting on the Wing
Start with one bird. Audubon Society and Cornell Lab of Ornithology, sponsors of the Great Backyard Bird Count, tell us that “Carolina wrens are one of the most familiar and beloved birds of backyards in the eastern U.S., especially in the southeastern states where they are most common. Great Backyard Bird Count participants regularly report these “perky and vocal birds.”
In Maryland, last year’s Carolina wren count totaled 605, spotted one or two at a time in backyards across the state. Count data suggest that Carolina wrens are extending their range northward from Georgia, North Carolina, South Carolina and Virginia, where they are consistently among the top 10 most commonly reported species.
During last year’s count, I spent about an hour per day in dribs and drabs watching and counting the birds. All 179 birds I spotted were as common as the Carolina wren, though I didn’t see one of those. A blue jay poked about in the hedge row. A mockingbird flitted through the trees. At the silver maple, the two blackbirds, nuthatch, junco, titmouse, mourning dove, house finch, Carolina chickadee, downy woodpeckers, cardinals, house sparrows, grackles and a single robin came and went.
This is just what count organizers want.
“We aren’t particularly interested in the extreme rarities. Our focus is more on the commoner birds and keeping them common,” organizers say. They also don’t worry much about your identification skills. They create regional lists that rule out impossibilities and put caps on the numbers for any particular birds. “You can’t report a roadrunner in New York using a correct zip code,” they say. “And your report will not be accepted for 100 downy woodpeckers.” The large numbers of reporters also overwhelm bad data.
Does Robin Redbreast Hate the Snow?
The professionals are particularly interested in the effect of snow on bird migration. Information collected by the Great Backyard Bird Count makes the case that American robins are most likely to be reported in areas with little or no snow. More than a dusting keeps the robin count low. Regions with an unusually low snow cover are likely to report more robins than usual. The data hold up over several years of observation.
Over 228 reports last year tallied 2,429 robins continent-wide (an average of 10 per report). Robins are found locally at any time of year, and a flock of a dozen came through my yard in last week’s snow. Robin’s reputation as a harbinger of spring is not, however, entirely misplaced.
“During years when food is available and easy to acquire,” ornithologists have discovered, “species like American robins, killdeer and Steller’s jay may remain in more northerly locations or at higher elevations than in years when food is not as plentiful or is more difficult to acquire.” Birds that spend winter closer to their summer haunts are able to beat the returning crowd to their breeding grounds, selecting the best places for successful families.
In 1999, counters reported huge numbers of robins farther north than during previous years. Using that data, the professional scientists were able to show that the high numbers of American robins matched reports of low snow cover, pointing to increased food availability.
Information collected during the 2001 count suggests that American robins, red-winged blackbirds, white-throated sparrows and northern flickers avoid areas with snow cover, but data is needed from this year’s count to bolster the evidence. I wonder if the dozen robins I saw last week are a contradiction.
Flying North
In 2002, reports found other birds farther north than usual. Frank Gill of Audubon and John W. Fitzpatrick of Cornell Lab of Ornithology reported that sandhill cranes were sighted along the length of their eastern migration route in a clear band running from Florida to Michigan. Possibly due to last winter’s mild weather, a greater number of cranes were reported along the northern end of the route than during the 2001 count. More red-winged blackbirds were also counted at their northern limits.
Citizen scientists add to the stockpile of information by reporting snow depth (measured by yardstick) along with bird sightings. Reports of no snow are just as important. The data will help create a map illustrating the relationship between snow depth and the abundance and distribution of the birds reported across North America.
Tracking West Nile
Data gathered this year may also show the impact of West Nile virus on bird populations. The largest epidemic of meningoencephalitis (swelling of brain and spinal cord tissue) ever recorded in the western hemisphere, West Nile has raced across North America since 1999 to infect 44 states, five Canadian provinces and the District of Columbia. Any drastic changes in overall bird populations not accounted for by weather or other known factors may shed light on the devastations brought about by a virus that claimed the lives of hundreds of thousands of birds, 241 humans, 4,300 horses and three alligators in 2002 alone.
Join the Thousands Counting Millions
In all last year, 46,546 checklists from backyard birders counted 4,727,536 birds, and helped document the ranges of common winter birds like dark-eyed juncos, black-capped chickadees, mourning doves and spotted towhees. Such discoveries cost a lot less than a mission to Mars, Jupiter or the Moon.
The Great Backyard Bird Count February 14-17 is a free adventure in discovery sponsored by Cornell Lab of Ornithology and National Audubon Society: www.birdsource.org.
