Walk into any healthy hay field and you will see a nice array of bird species. Song Sparrows, Red-winged Blackbirds will be very common, but other species such as Eastern Meadowlark, Bobolink, Savannah Sparrow and Vesper Sparrow may be common. Even more, Grasshopper and Henslow’s Sparrow can be found along with a whole host of other birds.
But when Europeans first came to Eastern North America, a lot of those species were very uncommon (some still are) if present at all. I think it is safe to assume that Song Sparrows and Red-winged Blackbirds, two species which can be found in a number of different habitats were common. Savannah Sparrow was likely pretty rare, except along the coast where they would be found in coastal dunes. But the rest? Hard to tell.
Certainly these birds were found in parts of the Ohio Valley and into the Mississippi River valley and the great plains, but the great ‘wall of trees’ prevented these birds from moving much further east, that is until people came.
As people came, they cut down the forests and made fields and pastures for grazing. No longer having any habitat blocking their way and a sudden increase in available habitat (thus lowering the competition for nest sites) many of these species populations exploded and moved North and East. By 1900 in many areas grassland birds were more common than the native forest birds! Ruffed Grouse and Pileated Woodpeckers were in serious trouble. This was a perfect example of man unintentionally assisting nature.
But there is the good. Who doesn’t like watching a male Bobolink sing his bubbly song over a field in early summer? But then there is also the bad, Brown Headed Cowbird. These birds which spent their time following the large herds of Buffalo which roamed the plains, didn’t have time to nest so they simply laid their eggs in other birds nest. These adopted chicks often killed their siblings and there is nothing more sad than watching a pair of Yellow Warblers attempting to keep a Brown headed Cowbird chick fed. On the other hand you have to admire the Brown headed Cowbird. By 1900 there were no Buffalo left to follow, but there was also nothing stopping the birds from moving east into areas where birds have no experience with them. Even today as habitat fragmentation continues, due to limited space Brown headed Cowbirds now bother the nests of Wood Thrushes and other woodland birds, species they never had contact with in the past.
While all those grassland species were great to have, forest birds suffered (over logging was like a 1-2 punch, although clear cutting in the Adirondack Mountains of New York State led to Golden Eagle nesting, however the forests have returned and the habitat is no longer suitable for Golden Eagles and thus none have nested in over 30 years in New York). Song birds were not the only birds to benefit, Raptors such as Northern Harrier, American Kestrel and Short-Eared and Barn Owlsalso benefited. Many of those species were likely migrants, but the new available habitat allowed many to try and nest. Sadly some birds such as Short-Eared Owl and in many parts of New York State, Barn Owlhave been extirpated as breeders.
Introduced birds have also benefited from farming. Canada Goose (which isn’t exactly introduced) decided that farm ponds and open fields are just as good as tundra ponds. House (English) Sparrows and European Starlingswho have no trouble associating with humans found plenty of open space. And what farm is complete without a flock of multi colored Rock Pigeons flying around? But one introduced species really benefited from farm land, Ring-necked Pheasant. This species has reached the point where there is very little stable population in the wild anymore in many parts of Upstate New York. The New York State Department of Environmental Conservation spends a ridiculous amount of money for restocking of this species, even though there is little habitat to support it. Mostly they become eaten, by either human recreational hunters or other animals.
But the grassland reign was short. As farming slowly began to die, second growth took off. Thus lots of small tree’s and shrubs and other woody plants. These habitats are not suitable for most grassland species, but became perfect for species such as Gray Catbird, Northern Mockingbird, Northern Cardinal, Brown Thrasher and Blue-winged Warbler.
In recent times the forests have reclaimed many of the former farms and it is not uncommon to go walking in mature woods and find an old stone wall or field marker. Woodland species have rebounded to almost historic highs and some may be even at levels of pre-colonial days. But this idea of ‘nature’ taking back what is hers, has crushed grassland birds. Not only do they have serious competition between rival males and species, but a lot species have to contend with modern farming techniques. The combined effects, have had devastating effects. Many grassland species are also wary of humans and are easily driven out of suburban areas. Also being forced to nest in less than ideal habitat makes them prime for predators such as Blue Jays, American Crows, Racoon’s, Skunks and Weasels. The return of the Coyote likely hasn’t helped either.
Grassland birds also seem unable, to adjust to new habitats, that is except the Brown Headed Cowbird which continues to thrive in many areas.
I invite everyone to go and take a walk in a field right now (wear Orange its hunting season). Right now its Sparrow time, with zillions of Song Sparrows, but also lots of Savannah, Vesper, White-throated and White-Crowned Sparrows. Fox Sparrows should be arriving shortly (if they haven’t already). Watch for a Gray Ghost (a male Northern Harrier) cruising over the fields or to see the tawny fluff of a Short-Eared Owlsitting on a fence post. In a couple of weeks, look for Northern Shrike and Common Redpolls feeding on weed seeds. Many of these species would not be as visible, common or stay as long if it wasn’t for the beneficial effects of farming.
The next segment will look at how certain farming practices have seriously affected certain species. We will look at the top five species of grassland birds in peril.