From mid-December through early January, teams of birders scour the landscape looking for any and every bird they can find. The purpose? To count the wintering birds — all of the wintering birds. The name of this event? The Christmas Bird Count (CBC).
Sounds like a crazy way to spend a winter day, you say? You may be right, but there are a lot of people willing to participate in such craziness. Ohio alone hosts over 50 counts, and there are several thousand Christmas Bird Counts spread out across the U.S. and into Mexico and Central America.
The CBCs are actually a long-running Audubon tradition, established over 100 years ago. They have become one of the longest-running volunteer bio-monitoring projects in the world. The rules are simple: count all the birds you can in a 15-mile-diameter circle on one day between Dec 14 – January 5.
It seems simple, but the devil is in the details. Since few counts can hope to completely cover every square foot of their circles, most counts focus their efforts on the best bird-finding locations within their territories.
So why bother going out in the cold and working hard to note every bird seen? Besides providing a good excuse for birders with cabin fever to venture outside, the Christmas Bird Count provides a unique, continuing dataset that documents the help of bird populations. Because the CBC has been going on for well over 100 years, scientists to analyze CBC data are able to document changes in winter bird populations all over the continent. For example, CBCs in our central Ohio area have recorded the changes — both positive and negative — as Columbus has grown from a small town into a major metropolitan, and Franklin, Delaware, and Pickaway counties have developed along with the city.
You might think that birding in the middle of winter is a hopeless task. But you’d be pleasantly surprised at the number and variety of birds that call Columbus and surrounding areas their winter homes. Central Ohio CBCs routinely find 70 or more species of birds, with tens of thousands of individual birds counted. Many are the ubiquitous urban birds one might expect: Ring-billed Gulls, Starlings, Crows, Cardinals, and House Sparrows. But there is also a variety of other, wilder species even in the city and more so in the surrounding rural areas: Mourning Doves, Red-bellied and Downy woodpeckers, Blue Jays, Carolina Chickadees, Tufted Titmice, American Robins, Carolina wrens, White-throated Sparrows, and American Goldfinches. Other formerly-uncommon winter visitors, like Flickers, Cedar Waxwings, Eastern Bluebirds, Mockingbirds, and Juncos, have become more common in recent years, perhaps attracted by the many fruit trees in our yards and feeders around our houses.
We even get many birds that you wouldn’t expect in winter in the middle of an urban area in Ohio. Large numbers of Great Blue Herons now winter along our creeks and rivers, and waterfowl have also started to linger in these areas and open ponds. Central Ohio counts often find 10 or more species of waterfowl, including lots of dabbling ducks and cormorants and Pied-billed Grebes. We also have a burgeoning population of winter raptors, led by Cooper’s hawks and Red-tailed hawks, which can be found not only in the countryside but even in most areas of the city. Bald eagles, almost unknown from the area just a few years ago, turn up frequently. Even secretive owls, like Great Horned and Barred, are still found in many of our wooded parks in both Franklin, Delaware, and Pickaway counties. We have even been getting increasing numbers of ‘half-hardy’ birds, species like sapsuckers, hermit thrushes, chipping sparrows, and even a few warblers, that are hanging on at the northern limits of their winter ranges.
Not all local winter birds are doing so well, however. Open country birds, like meadowlarks, blackbirds, harriers, and some kinds of sparrows, have definitely declined, particularly in more urbanized areas. Marsh birds like rails, Coots, snipes, and Swamp Sparrows have also become very infrequent as their wetlands have been filled in. Other birds have slowly disappeared for no obvious reasons. Red-headed Woodpeckers were formerly regular in the circle, but are now rare, possibly reflecting the steady fragmentation of our remaining upland oak forests. Eastern Towhees have declined to the point where they now hang on only in a few park areas. Hopefully these trends can be stabilized or reversed, and continued counts are the most direct way to monitor this change.
So the bottom line is that each CBC needs observers. The more teams we can field for each of the CBCs, the better our chances of getting good, representative counts of our area’s winter birds. And, for those who enjoy the thrill of the chase, the better our chances of unearthing something totally unexpected! Even just walking around your neighborhood and watching your feeders can be valuable. Please join the crazy tradition of the Audubon Christmas Bird Counts.