As April in Maine creeps along, the trickle of returning migrants has become a steady stream. Ducks, herons and egrets are increasing in number, and we have an out-of-range trumpeter swan in Biddeford.
Sparrows multiply daily, and even swallows and the first warblers, as well as other songbirds, are making an appearance. Raptors are returning as well, their numbers documented by an official counter atop Bradbury Mountain in Pownal.
I plan to make it up to Bradbury Mountain to join the hawk watch this weekend. This particular geographical feature just so happens to be in the flyway for those migrating birds of prey and has provided a reliable means of tallying the numbers of returning birds. To date, 1,098 raptors have been counted this spring, with the highest daily counts going to osprey, American kestrels, sharp-shinned hawks and now broad-winged hawks.
Those of you who read this column probably already know birds of prey are a favorite of mine. I never tire of watching them, and catching sight of one unexpectedly is a guaranteed thrill — as it was one day while on lunch break at work.
I caught movement out of the corner of my eye and turned to see a large raptor cruising low over a utility pole clearing. The area was a mix of meadow and wetland — a favorite habitat of the northern harrier or marsh hawk.
At first, all I could see was the bird in silhouette. As it turned and the angle of light changed, I was delighted to see it was a male harrier. Unlike most other raptors, harriers are sexually dimorphic in their plumage. Whereas the female has rich brown upper-body feathers and a buffy underbody, males are silver-blue-gray above and clean white underneath, with stark black linings to their wing tips. The visual effect is dazzling.
I watched the bird as it coursed over the wetland, enjoying its buoyant, almost mothlike flight. Reading up on its hunting strategies and modes of travel in “Hawks in Flight” by Pete Dunne, David Sibley and Clay Sutton, I thought the description of a harrier’s hunting flight very apt: “A low, cruising flight … punctuated at intervals by pull-ups, wing-overs, and drop-pounces.” The harrier was employing all of these moves and more as it flew over a low rise and did not reappear. I imagined it was successful in its hunt — it may have caught a vole or small songbird.
Getting back to the list of migrants and plans for my weekend, I hope the trumpeter swan stays put long enough for me to go see it. This bird is usually not found farther east than the Great Lakes and has small, scattered breeding ranges throughout the midwestern United States, northwestern Canada and Alaska. It winters in the Pacific Northwest, so finding one here is an occurrence of note, at least in the present day. Stay tuned.
Speaking of birding trips, Maine Audubon’s “Neighborhood Bird Walks” throughout Greater Bangor will start up on May 2. Trips to birding hot spots for people of all ability levels will take place throughout the month; visit http://habitat.maineaudubon.org/activities/Neighborhood-Bird-Walks/1006/ or call the Fields Pond Audubon Center at 207-989-2591 for more information and to register.