Great Gray Owls are a bird of dense, northern boreal forests, rarely venturing south of Canada into the northeastern U.S. during winters when their rodent prey is scarce. Superficially similar to, and belonging to the same genus as, our common Barred Owl, this species is distinguished by its larger size, bright yellow eyes, and black-and-white “bow tie” below the gray facial disc. Southward invasions, or “irruptions”, occur sporadically and can involve substantial numbers of birds. In Vermont, only eight Great Gray Owls have been confirmed previous to this one, and three of those appeared during the winter of 1984. One bird remained in St. Johnsbury for almost seven weeks. An infamous Great Gray that lingered on a farm in Massachusetts for two months in 1973 attracted more than 3,000 birders!
Although the Great Gray Owl cuts an imposing and massive figure, its bulk is made up largely of feathers, which allow it to withstand the bitter cold of boreal winters. The species’ body mass is considerably smaller than that of two other large, northern owls—the Great Horned and Snowy. Preying primarily on voles in the eastern part of its range, the Great Gray uses its superior hearing to locate rodents beneath the snowpack, plunging through the surface to seize them. An apparent scarcity of red-backed voles in eastern Canada this winter probably accounts for the rare and unexpected appearance of this individual in Vermont, as well as the steady stream of Barred Owls that have been reported statewide in recent months.
Although a distant second to the Burlington owl, waterfowl and gulls also provided birding interest during the past week. Snow Geese have begun their return journey to Arctic nesting grounds, with reports of 100 off the mouth of Otter Creek, 515 in Cornwall, and 500 off Grand Isle. Canvasbacks continue to make an unusually good showing on Lake Champlain, with several flocks of up to 23 birds off Charlotte, Colchester, and the islands. Single Redheads were observed in Colchester and off Allen Point, while the male Tufted Duck remained off the Colchester Railroad Causeway, where it has been reliably present for several weeks.
Although gulls pose an identification nemesis for many birders, careful searching of Lake Champlain yielded three rare species last week. A third-winter Lesser Black-backed Gull in Kellogg Bay on March 22nd was the most unusual. This European stray has only been confirmed in Vermont on six previous occasions, the last in January of 2001. More regular, but still noteworthy, were seven Iceland and two Glaucous Gulls between Kellogg Bay and Basin Harbor. These Arctic-breeding species are probably more common in winter than records indicate, but may be overlooked by many birders.
Other highlights included a remarkable concentration of 25 Bald Eagles scattered along the Lake Champlain ice and trees between Kellogg Bay and Basin Harbor on March 22nd. American Woodcocks are now engaging in their spectacular aerial courtship displays, with the first report coming from Shelburne. The past week’s consistent north winds and cold temperatures kept most spring landbird migrants to our south, but the season’s first Eastern Phoebes appeared in Starksboro on the 18th. The next push of southerly winds should bring a pulse of early migrants, but for now enjoy the lingering Bohemian Waxwings, Pine Grosbeaks and Common Redpolls that continue to be reported around Vermont.
You can explore all the birds reported last week in Vermont and add your own sightings at Vermont eBird.-by Chris Rimmer