Buttonbush swamp in winter, Oshtemo Township. Photo by Richard Brewer
Whatever else Christmas may mean to a birder, it definitely means the Audubon Christmas bird count.
The National Audubon Society sponsors a continent-wide set of local counts to be taken some time around Christmas, specifically on a single day between December 14 and January 5. Local groups of birders count birds in circular areas 15 miles across. What most groups do is divide the circle up into sectors and maybe sub-sectors and assign a party to each. The party may be one person ambling ( or driving) along and censusing birds by himself or herself. Or it may be a small group, but if the group gets above about four, it would be more efficient to break it and the sector up.
A circle of 15-mile diameter doesn’t sound very big, but it is. It amounts to a little more than 175 square miles. A square mile is 640 acres. Except for a few sophisticated urbanites, most of us out here in the part of the US where the grid rules–where the land is laid out in townships, ranges, and sections–most of us have at least a vague idea of what 40 acres looks like. A square mile (640 acres) is one section, which can be divided into quarter sections–each 160 acres–and each quarter-section can be divided into quarters. These are each 40 acres, as in the back forty.
So if a local bird group divides its count circle into 20 slices or chunks, the average size will be between 8 and 9 square miles, or between 5000 and 6000 acres. The average bird club is making a good showing if it has 40 birders out and counting, or in other words, about 2 birders per sector.
The point of all these numbers, if there is one, is that most Christmas bird counts are a bit understaffed.
But that’s not a serious problem. First, the main point of the count is fun, of a sort. It’s fun to get out and brave the elements in the coldest, darkest part of the year. The Christmas count is the birder’s winter solstice festival. And it’s fun to see what birds are around, what birds are braving those conditions along with us. A few bird species have normal body temperatures around the same as humans, 98.6 degrees Fahrenheit, but most of the small birds we count at Christmas have temperatures up around 105-110 degrees. It takes a lot of feeding during the daylight hours, a lot of sunflowers seeds and suet or hibernating insects and fat from a deer carcass, for a chickadee to stay alive for 24 hours in winter.
Christmas Counts do provide data for scientific purposes. They provide a very accurate map of the winter range of the most of the bird species. They provide passable information on abundance of many of the species, expressed as an index value, usually number of birds per party-hour.
But except for a few species, a Christmas count almost never gives us the actual number of birds, Song Sparrows or Black-capped Chickadees or Cedar Waxwings, in our 15-mile circle. On a well-regulated count, it might be possible to arrange things to tally every individual of an uncommon, conspicuous species, especially one of a well-defined habitat. For example if there are only three areas of open water in a count circle and we cover all three, we can probably get a pretty good count for the ducks. A good count for the time when somebody visits the three areas of open water, that is. There’s no guarantee that some ducks from our circle didn’t fly a few miles to a different circle just before we counted.
The first Christmas Count I took was in 1949, when I was a sophomore in high school. Bill Hardy, Kenny Stewart and I took a Murphysboro, Illinois, count on December 27th. Hardy was the instigator. He was the oldest, the best birder, and also more of an organizer than Kenny or me.
Things were more casual then. We just decided to take a count, figured out our circle, took it, typed up the results, and sent them to Audubon Field Notes, which published ours along with the whole batch of counts from around the country. Audubon Field Notes is called American Birds now, and the figures that get sent in on forms go into a database and the published Christmas Count consists mostly of summaries for the different geographic regions. The total number of counts today is well over 2000, mostly in the U.S., but quite a few in Canada, and some in Latin America and the Caribbean, and a few elsewhere.
We took the Murphysboro count a few more times. I can’t remember when we stopped, but eventually Hardy went off to graduate school at Michigan State and a little later I went off to the University of Illinois.
I ought to mention that the Murphysboro count was not the first southern Illinois Christmas bird count. A few years before, William Marberry, a botanist and all-round naturalist on the faculty at Southern Illinois University, had taken a count south of Carbondale and, I think, including Giant City State Park, or part of it. He may have repeated the count another year, but I’d have to get to the library to look at the back issues of Audubon Field Notes to be sure.
I’ve occasionally gone on a couple of counts in a year, but I’ve also missed an occasional year. Ordinarily though, even if I’ll be away from home, I try to get in touch with the organizer of a count near where I’ll be at Christmas time and ask if I can join in. Most groups are happy to have visitors help out. Most of the other places where I’ve helped seem to be in places that are warmer in the winter than Michigan.
Most counts that have been running for a long time have a tradition as to when the count is held. The Kalamazoo count is supposed to be the Saturday after Christmas. When Christmas is on a Saturday, as is the case this year, this means that the count would be held on New Year’s Day. That would seem to be no problem, except that the tradition for the Southern Kalamazoo County Count (SKCC) is that it be held on New Year’s Day.
The SKCC is relatively young, started for the 1975-76 count. It’s odd in that it is a rectangle rather than a circle, hence it doesn’t qualify for the National Audubon database. One advantage of a rectangle is that, here in our gridded landscape, you nearly always know exactly whether a bird is in or out of the count area, depending on which side of the road it’s on. Sometimes you’re not so sure about a bird near the edge of a circular count area. On the other hand, circular count areas are the most compact shape and accordingly have the least amount of edge to worry about.
I understand that in the clash of tradition this year, SKCC won. The Kalamazoo Count is on Sunday, 26 December 2010, rather than on the Saturday after Christmas, 1 January 2011. What would Frank Hinds say, or Theodosia Hadley? Or Charlie Cook, or Helen Burrell, or Bob van Blaricom (Buckeye Bob), or Harold Wiles?