As I begin the morning no longer do I hear the chorus of song from the Northern Mockingbird, Carolina Chickadee and Wren. Instead I hear the racket of hundreds of European Starlings, Common Grackles and Brown-headed Cowbirds.
Every winter (of recent) it seems large aggregates of these birds steal the sky and branch of every naked tree of some urban townships. Many researchers conclude this phenomenon is due in part to erratic changes in our climate, but moreover this behavior has been an effect of urbanization. While most Neotropical migrants head South for the winter others stay due to the regularly available food sources from weekly garbage collection to those dependable suet and seed feeders most nature lovers have hanging in their backyard.
Besides food the urban environment provides safety for birds who see poorly in the dark evening hours. Sources of light such as streetlights and outdoor security lights provide these birds protection from the ever acute-eyed owl.
Yet the racket from them is not the only problem. These birds make a large mess with their accumulated defecation. Also, because of the increased population size and perhaps lack of ample resources many die; causing disease issues for domesticated animals.
Despite what seems like an awful phenomenon, even for a bird lover, it only last a portion of the year before these aggregates disperse. Then once again I will hear the more diverse chorus of song from the Northern Mockingbird, Chickadee and Wren.