The mysterious, flute-like song of the wood thrush was once common along the greenway in summer, but the bird and its song have disappeared during the breeding season. The last nest I observed was destroyed by a cat. For those unfamiliar with cowbird trickery, females place their eggs in nests of other birds and then leave child-rearing to the unsuspecting victims. The female cowbirds also often remove eggs of their victims, and the aggressive young cowbirds usually outmuscle their nest mates when foster parents bring food. All of the yellow-throated vireo nests I have observed in the Indianhead greenway have been parasitized by cowbirds.
Cowbirds also have heavily parasitized nests of the red-eyed vireo and parula warbler.
Greenways' shape can bring danger, not shelter Similar problems have been documented in other greenways and stem in part from the narrowness of such features. Homes are easily seen at any point along the Indianhead greenway. The homes harbor cats that prey on birds and other small animals, they have feeders and grassy lawns that keep parasitic cowbird numbers high and they supply a steady stream of seeds that fill the greenway with intrusive exotic plants. Of course, corridors and greenways are not meant to function solely as breeding habitat for birds. They are supposed to provide salamanders, snakes, mammals and other land-bound animals with a means of moving from place to place.