This evening I was looking at e-Bird data, particularly checking for regions where there is enough "old" data (pre-1990) to maybe get some sense of decade-to-decade trends. In most regions there really isn't much older information to speak of; but one of the places there is, is the Piedmont. This is the plateau between the Appalachians and the Coastal Plain from Alabama to Maryland; pretty much the I-85 corridor and much of metro DC. This is where I grew up (Atlanta), and some of that pre-1990 data is actually mine. So I looked at the abundance bar graphs for before 1990 and after 2000 and compared species by species. It was frightening.
As a preface, note that the Piedmont has underone MASSIVE and RAPID land use change and population growth in this time. The earlier landscape of farms and oak-pine woodlots separating discrete cities has been replaced wholesale with suburb upon suburb. Over vast areas the suburbs have run together; what we used to call BosWash (the northeastern urban corridor from Boston-Washington) is now more like Bostingham, having grown all the way to Alabama. This is in fact one of the major reasons Peggy and I do not live there anymore. And what has happened to the common birds here, in my quick and dirty estimate?
Well, for four species, the change has been good: Canada Goose, Ring-billed Gull, Fish Crow, and House Wren have all increased. But for the others, it is a catastrophe. About 90 common (at least formerly
common) species seem to have declined notably region-wide; nearly 50 of these have declined quite substantially, many to the point that a species that was common in my youth is now rather scarce. This includes residents, breeders, winterers, and transients; it cuts across the habitat preferences, migratory patterns, and taxonomic groupings. We can't blame this on far-away lands; this is a home-grown distaster. Folks, 90 species is right about half of all the species that used to be common here.
A sampling of the once widespread species that appear to have dropped off sharply include: Northern Bobwhite, Green Heron, Great Crested Flycatcher, White-eyed Vireo, Northern Rough-winged Swallow, Blue-gray Gnatcatcher, Swainson's Thrush, Brown Thrasher, Tennessee Warbler, Chestnut-sided Warbler, Common Yellowthroat, Field Sparrow, Savannah Sparrow, Blue Grosbeak, Indigo Bunting, Eastern Meadowlark, Rusty Blackbird, and Orchard Oriole. The main thing all these birds have in common is that they don't like neat, tidy, Dixie-style suburban landscaping. They like brushpiles, weedy edges, farm ponds with brambly shores, mixed species woodlots, underbrush, field and pastures... all the landscape elements that vanish with residential development. When I was a kid in Atlanta, all these things still existed even around the older neighborhoods in the city. But thanks to "infill" development they are a thing of the past. The Piedmont is one of the worst case examples, perhaps; but the pattern is happening everywhere.
Land use, folks. Right here at home. This is the biggest threat to our birds and all the rest of the entities that comprise our ecosystems. We can fight all the global warming and tropical deforestation we want, but if all we have left back home is shade trees, manicured lawns, strip malls, and soccer fields it hardly matters. Weeds and woods and willows and brambles and "trash trees" can
be incorporated into our landscapes from downtown to the outermost edges of the suburbs. Sad, that it is landscaping fashion and the inexpensive gasoline-powered lawnmower that are eradicating our birds.