Breeding Bird Surveys
For many of us birding is a sport. How many species can we see in a day, a week or a year? How many species are on our county, state and life lists? Those activities provide a great deal of pleasure and, as an avid lister myself, I do not decry them. In fact they can also contribute indirectly to the science of ornithology: when organized here by the Buffalo Ornithological Society, those observations extend our knowledge about changes in arrival and departure dates of migrants and the appearance or disappearance of rare species.
Those activities do not, however, tell us much about bird populations. Many of us have a sense that the numbers of some species are increasing while others are declining, but that sense doesn't stand up to careful scrutiny. Anecdotes lead us to believe that birding was better in "the good old days."
One kind of count, the North American Breeding Bird Survey based at the United States Geological Survey's Patuxent Wildlife Research Center, does provide population comparisons.
These are annual counts over established 24.5 mile routes. As I have for a half dozen years, a few days ago I joined Mike Morgante to cover his Hamburg survey. We began a half hour before dawn (just after 5:00 a.m.) at our starting point with Mike standing beside my car counting the species he could see and hear for three minutes. He called out the numbers for me to record - "two yellowthroats, a catbird, three house sparrows" and so on. Time up, he jumped into the car and we sped off a half-mile to the next stop. We continued for just over four hours recording 1008 birds of 59 species. My job was done then but Mike had to organize the records and report them to Patuxent.
This route has been surveyed for 47 years. Beyond that, in 2014 nearly 3000 of these routes were covered. Clearly, that amount of field work each year by volunteers across the United States, Canada and more recently Mexico provides a huge volume of meaningful data.
But even this one route provides interesting information. As I write, I have a spreadsheet that covers all of those 47 years. (This route was first censused in 1967 but 1981 and 1982 were missed.) Let's see what information we can glean about population changes. Some of it may surprise you.
Clearly some species have increased strikingly. Among them are some that we don't realize were once uncommon. Canada geese were never reported before 1991; this year there were 49. Ring-billed gulls averaged 2 per year through the 1980s; in this decade they average over 100. Southern birds moving north include: Red-bellied woodpeckers, never reported before 1997, today are more than twice as common as hairy woodpeckers; tufted titmice, never recorded until 1994, this year 11. On the other hand pheasants were common on early counts with 20 counted in 1969; only one has been recorded since 1989.
The native birds you feed in winter are thriving with almost three times as many here now as there were before 1980. And bluebird houses are helping too: only recorded once before 1996, in this decade bluebirds have averaged over six per count. You may find it hard to believe, but both starling and house sparrow numbers in this decade are less than half those in the 1960s and rock pigeon numbers are also way down.
And what about warblers? We so often hear of their decline. Not so here: their numbers have remained the same. In fact the total number of birds recorded each year has remained nearly constant as well.
There are, of course, non-bird changes that affect these counts. A change in the person doing the identification can make a difference. So too do changes in the landscape especially with new housing appearing, but this reflects increasing human population density and needs to be taken into account.
There are 13 survey routes in western New York, two of which, Sheridan and Nashville, have not been run for several years. I know the Nashville route because I surveyed it myself for many years until my hearing declined. I urge fellow birders to consider taking over these counts for next year's census. Contact me for more information.-- Gerry Rising