Monday, February 15, 2010

GBBC Day 3: The Peregrine Show


For day 1 and day 2 of the Great Backyard Bird Count, I covered my local patch, Donaldson Park, in addition to some feeder watching. Yesterday I stayed in my town but covered a different location where I rarely bird. The site is a very small nature reserve adjacent to Donaldson Park. It used to be a marina but was purchased and remediated by the county after the marina closed its operations. Now it is covered partially with early-succession vegetation.

On most days one can find a few sparrows around the edges of the site, but yesterday the snow depth forced most of them to seek food elsewhere. (As I was leaving the site later, I found two dozen White-throated Sparrows and one American Tree Sparrow at a house with feeders just outside the site.) I could see that there were still many Common Mergansers on the river. I counted 17 and found one female Hooded Merganser among them. Gulls were also present but in smaller numbers; there were only a few dozen of each of the common species.

As I was watching the gulls, a lot started taking off, and three American Crows arrived and started cawing. This could only mean one thing – a predator. Expecting an eagle, I looked up and instead saw an adult Peregrine Falcon calling loudly and flying slowly over my head in level flight. I watched until it disappeared over the far treeline. A few minutes later it returned, this time accompanied by a second, slightly smaller, adult Peregrine. The size difference was significant enough that I think these were a male and a female. The female continued to call and maintained level flight. The male wove back and forth over and around her, at times appearing to tag her on the back. After disappearing over the trees again, they came back two more times, executing the same maneuvers. This is not listed among the falcon's courtship displays in my raptor books or in Birds of North America. However, it seems likely to be some sort of mating-related aerial play given the time of year and lack of aggression.

Despite walking around the site, I did not add many more birds after seeing the Peregrines. On my way out I saw the sparrows mentioned above and a small flock of Cedar Waxwings. The birds around my home were mostly the same as usual except for a Northern Flicker that flew over the yard. In the evening, I walked around the neighborhood to listen for owls, but I did not hear any.