By Bryan Stevens
I took part in the annual Fall Bird Count organized each year by the Elizabethton Bird Club. This year’s Fall Bird Count — the 49th consecutive count conducted by the EBC — was held Saturday, Sept. 29, with 50 observers in 13 parties covering parts of five adjacent counties in Northeast Tennessee. The count is the only fall survey of birds conducted in the entire region.
The total of 127 species tallied (plus Empidonax species) represented a slightly higher total than the average of the last 30 years, which stands at 125. The all-time high of 137 species was established in 1993. Compiler Rick Knight noted that two very rare species were found this year: a purple gallinule at Meadowview Golf Course in Kingsport, Tennessee, and a black-legged kittiwake on South Holston Lake in Bristol. The kittiwake was first found on Sept. 27 and lingered long enough to be observed during the count.
Shorebird habitat was scarce due to high water levels at most sites, thus only one species was found other than killdeer. Warblers were generally found in low numbers, although 23 species were seen. No migrant sparrows had arrived yet. Blackbirds, too, were scarce. Some regular species were tallied in record high numbers, likely due to the above-average number of field parties. Broad-winged hawks were numerous, part of a notable late flight likely due to unfavorable weather conditions preceding count day.
My party included retired Milligan College biology professor Gary Wallace as well as Brookie and Jean Potter. We counted birds in the Elizabethton area around Wilbur Lake, along the Watauga River and on Holston Mountain. We observed two large kettles of migrating raptors during our time on Holston Mountain. The term “kettle” is a collective one for a group of migrating raptors. In more general terms, a kettle can refer to any flock of birds of prey. The term is used only in describing raptors that are soaring or flying. Although a few black vultures and turkey vultures drifted on the warm thermals rising off the slopes of Holston, the majority of the raptors in the two kettles we observed were broad-winged hawks. We ended the day with a total of 41 broad-winged hawks on our list. Later we learned that count participants found an amazing total of 321 individual broad-winged hawks, which represents a new high count for the Fall Bird Count for this species.
Southwest Virginia is home to the Mendota Fire Tower Hawk Watch, which has been ongoing for decades on Clinch Mountain. The annual autumn survey is currently supervised by Ron Harrington, a long-time member of the Bristol Bird Club. This has been an exceptional year for this particular hawk’s migration. In a post to the list-serve Bristol-Birds, Mike Sanders of Bristol, Virginia, reported that while talking with Harrington on Sept. 29 at Sugar Hollow Park, they happened to glance skyward and noticed a large flock of hawks passing overhead. One kettle contained an estimated 75 broad-winged hawks. “Just goes to show they can be anywhere migrating, not just up on a mountain top,” Sanders wrote in his email.
The broad-winged hawk is known by the scientific name Buteo platypterus. The genus, buteo, includes about two dozen large raptors that are often dominant avian predators in their respective habitats. The species is known for migrating in large flocks every autumn to return to wintering grounds far to the south as far as Mexico and Brazil.
The broad-winged hawk’s counterpart in the western United States is Swainson’s hawk, which shares the broad-winged hawk’s inclination for migrating in large flocks. Swainson’s hawk is named for William John Swainson, the famous 19th century English naturalist I mentioned in last week’s column in connection with Swainson’s thrush. “Each autumn, nearly the entire breeding population of the Swainson’s Hawk migrates from the temperate zone of North America to wintering areas in South America,” according to a profile posted at the website Birds of North America. The website notes that those Swainson hawks that migrate out of the prairie region of Canada must undertake a flight of more than 6,200 miles to reach their wintering habitat. They will repeat this long-distance feat again in the spring. This distance places Swainson’s hawk second among raptors only to that of the Arctic Peregrine Falcon.
Other raptors in the region include Cooper’s hawk, sharp-shinned hawk, red-tailed hawk and red-shouldered hawk. These raptors feed on everything from rodents and reptiles to various insects, amphibians and songbirds. There’s one hawk, however, that turns to another source of prey.
Ospreys, which are also known as fish hawks, have also been prevalent this autumn. I enjoyed watching an osprey perched in a tree along the Watauga River while leading the first of the Saturday October bird walks at Sycamore Shoals State Historic Park in Elizabethton, Tennessee. The osprey put on a great show, stretching its wings and posing for photographs taken by several walk participants.
Ospreys migrate through the region in spring and fall, making sightings more likely along lakes and larger rivers. I see them even more often when I travel to South Carolina, where these medium-sized raptors are common along the coast and in wetlands.
Actually, any body of water, from river or lake to pond or marsh, can provide adequate habitat for an osprey’s needs. The osprey is the only raptor in North America that feeds almost exclusively on fish. These hawks only rarely turn to other prey, such as rodents, reptiles and amphibians. Ospreys are a conservation success story. According to the North American Breeding Bird Survey, osprey populations grew by 2.5 percent per year from 1966 to 2015. As a result, this large brown and white hawk is common from coast to coast and all points in between. The 27 ospreys detected on the recent Fall Bird Count also set a new record for this species on this particular survey.
There are still plenty of ospreys and other birds to see before this fall migration season ends. The remaining Saturday walks at Sycamore Shoals State Historic Park are scheduled for Oct. 20 and Oct. 27. Participants should meet at 8 a.m. in the parking lot in front of the park’s Visitors Center. There is no charge, and the public is welcome. Bring binoculars to increase viewing enjoyment.