Thursday, September 8, 2016

Common Nighthawk

Yesterday, 7 September 2016, Erika and I returned to Northfield after a relatively unproductive local birding jaunt. As we entered the eastern edge of town, at the Roosevelt Parkway Wetlands, we noticed 50 long, sharp-winged birds swarming through the sky. “Aren’t those nighthawks?” asked Erika.
She was correct. These were our first Common Nighthawks of the year. I had about given up seeing them this year. Across much of their North American range, Common Nighthawks have become uncommon. The causes of these birds’ decline are unclear, but may included increased predation, pesticides (especially non-selective mosquito control), and/or habitat loss. In the later case, nighthawks prefer nesting on flat, gravel roofs, a design no longer favored by architects. Non-gravel roofs may not provide eggs sufficient camouflage, may get too hot for egg survival, and smooth roofs can result in eggs rolling away. Nighthawks are also often victims of roadkills and aircraft strikes (Brigham et al. 2011).