Weekly Bird Notes: A Noctural Owl Goes for Daylight

Typically a stealthy but vocal resident of Vermont’s deciduous forests, Barred Owls have been visibly on the prowl statewide throughout this winter. Sightings in broad daylight have been common, as evidenced by recent reports of a bird in downtown Burlington and many backyard or roadside sightings. In fact, the entire Northeast is experiencing a near-unprecedented incursion of Barred Owls. While exciting to birders and others who closely encounter one of these stately birds, the species’ frequent daytime appearances signal a time of hardship.

Barred Owls, whose distinctive “Who cooks for you? Who cooks for you?” hooting calls reverberate through Vermont woodlands in late winter and early spring, breed throughout the eastern U.S. and southern Canada. These sit-and-wait predators feed largely on small rodents, such as red-back voles and deer or white-footed mice. Apparently populations of these prey species have crashed in the Great Lakes-St. Lawrence region, forcing Barred Owls to move southward. Many of these dispersing birds are likely young-of-the-year, less experienced in the ways of the world and subject to becoming food-stressed. Their struggles to find prey probably account for daytime hunting, sometimes in unusual locations. Unfortunately, this behavior often finds them along roadsides, where small rodents have to leave their snow tunnels to make crossings. Many have been struck by cars.

The rash of Barred Owl sightings this winter is also reflected in irruptions of other northern predatory birds. Northern Shrikes have been present in Vermont in excellent numbers, and a recent unconfirmed report of a Great Gray Owl at the Burlington Intervale lends hope that more Canadian raptors are yet to visit. Birders should keep a watchful eye out for these wanderers. Our own resident Barred Owls should begin filling the night airwaves next month with their emphatic hooting, as the breeding season gets under way.

Other birding highlights of the past week included a lingering Snow Goose and a pair of Harlequin Ducks on Lake Champlain in Shelburne. More expected were 14 Ring-necked Ducks, 200 Greater Scaup, and 25 Lesser Scaup off Charlotte. A hardy American Kestrel was seen in Ferrisburgh on Jan. 19, while no fewer than 12 Northern Shrikes were reported statewide. Flocks of Bohemian and Cedar Waxwings continue to appear all over Vermont, as do Pine Grosbeaks and Common Redpolls. The week’s most unusual report was of a Lincoln’s Sparrow at the Burlington Intervale on Sunday, far north of its normal wintering range in the southern U.S.

You can explore all the birds reported last week in Vermont and add your own sightings at VTeBird.

By Chris Rimmer

The Redpolls

If you haven’t noticed flocks of Common Redpolls this year, you’ve either spent too much time in the deep woods or holed-up by the wood stove with the curtains closed. These small, lively boreal finches have been widespread this winter, frequenting feeders, fields, pastures and other open habitats across Vermont.

Sporting a black “goatee,” redpolls are named for their red cap or “poll.” Roughly the size of a Goldfinch, redpolls are heavily streaked on the flanks, rump, and back, with a gold conical bill tipped in black, and dark wings and tail. In winter, males have a rosy wash to their chest and sides, while females, such as the one pictured above, are buff-colored and more heavily streaked.

Along with several other arctic species, redpolls have moved south from their tundra breeding grounds as they typically do every other year in response to the biennial seed production of high latitude trees, especially spruce and birch. During these irruptive years, they may travel long distances in order to locate suitable food supplies. A Common Redpoll that was banded one winter in Fairbanks, Alaska, was recaptured the following winter 3,000 miles away near Montreal.

Gregarious and acrobatic, in winter, redpolls are most abundant in open grassy areas where their bouncy flight and rolling feeding flocks enhance the sensation of constant and exuberant activity. When scanning a flock of redpolls, be on the lookout for pale individuals that stand-out from the others in appearance. These are likely to be the less-common Hoary Redpoll (Carduelis hornemanni) which closely resembles the Common Redpoll (C. flammea), but is frostier overall.

While Common and Hoary redpolls have traditionally been considered separate species, recent studies show no genetic differences between them. However, valid arguments against merging the two forms into a single species have, for the time being, prevailed. These include measureable differences in vocalizations and bill shape (shorter in the Hoary), and the fact that they do not readily hybridize. Not to mention that maintaining both redpoll species gives winter-weary birders the chance to check-off two species instead of just one.

In addition to Common Redpoll and Pine Grosbeak sightings, which continue to be widespread this week, at least one Hoary Redpoll has been visiting a feeder in Waitsfield. Other notable sightings this week include a Red-necked Grebe in Button Bay, a very late American Bittern reported in Franklin, 7 Lesser Scaup in Shelburne Bay, 4 Long-tailed Ducks in Button Bay as well as at the Tri-town Water District Plant, and a Golden Eagle at Button Bay State Park. You can explore all the birds reported last week in Vermont and add your own sightings at VTeBird.

Weekly Bird Notes - Canvasbacks

Large rafts of winter waterfowl get me excited. With scope in hand, I can spend hours watching them follow food sources around a bay, perform courtship displays, and pop up to the water’s surface after foraging. The birder in me also likes to scan for rare and unusual species. Luckily for me and other birdwatchers in Vermont, it seems that unusual birds are rarely lacking in Lake Champlain, the Connecticut River, or Lake Memphremagog, Vermont’s primary hangouts for congregating waterfowl. This week, a pair of Canvasbacks has been frequently observed amongst a raft of Common Goldeneye in Shelburne Bay on Lake Champlain.

Canvasbacks are so-named for their whitish backs, the color of undyed canvas. Their white back contrasts sharply with their chestnut-colored head, and they are further distinguished from other diving ducks by their sloping forehead and bill. They are only likely to be confused with Redheads, a smaller diving duck that lacks the sloped forehead and has a black-tipped blue bill with a gray back.

Canvasbacks are among the least abundant duck species in North America. They breed along the deeper ponds, marshes, and potholes from Alaska and the Northwest Territories south to Colorado and Minnesota. They are omnivorous, consuming a mix of buds, roots, tubers, and insect larvae. During years of drought, when the ponds and marshes dry up and there is less food available, they will delay breeding, avoid breeding altogether, or move further north. A decreased rate of breeding, coupled with lower breeding success resulting from parasitizing Redheads laying eggs in Canvasback nests, helps explain their low overall population size.

Sensitivity to changes in available food resources, especially of plant tubers, has resulted in Canvasbacks changing their migratory and wintering behavior over the last 50 years. When food supplies were eliminated due to sedimentation and pollution on their traditional migratory stopover sites in Minnesota and Illinois, they utilized newly created habitats in impoundments along the Mississippi River. Their current migration routes see annual changes in abundance, partly in response to fluctuations in food availability. Large flocks overwinter in the coastal waters of the U.S. and in the interior south, where they historically used brackish waters with an abundance of food, but now adjust habitat use based on weather, habitat availability, and the level of human disturbance.

Other Sightings

A male Redhead was observed in the New York waters of Lake Champlain in Westport on January 6. A rare Three-toed Woodpecker was observed at Moose Bog in the Northeast Kingdom on January 5, the same location one was observed last winter. Although not highly unusual, a Great Blue Heron in Grand Isle on January 4 may be an indication of more open water and bare ground, leading to additional sightings of herons, kingfishers, buntings, larks and the like.

The official eBird stats were released this week. A record 6,047,650 birds were reported on 442,985 checklists submitted in 2007. Vermont ranked 14^th overall, 12^th in the U.S., for number of checklists submitted (10,755), possibly the highest per capita rate. Happy birding in ‘08!

You can explore all the birds reported last week in Vermont and add your own sightings at VT eBird.

Roadside Loon Rescue in West Brattleboro

A Common Loon was found a few days ago on the side of the road in West Brattleboro. It was in good condition and brought to the VINS rehabilitation center. It was probably getting hemmed in to a water body last week by the freezing temperatures and needed to make a quick escape. Loons and other seabirds sometimes mistake heat waves coming off roads for water bodies.

The exceptional thing about this bird was that it was banded in the Adirondacks in 1998.

Weekly Bird Notes: Songbird Snowstorm

The flock of small birds whirls around the hayfield like a snow squall finally coming to rest on the ground in front of me. Aptly named, the snow bunting is a bird of the high Arctic in the summer and cold Vermont fields during the winter.

According to reports on Vermont eBird, an online database for Vermont bird sightings, the earliest flocks arrived this year during the last week of October. Although the species tends to be nomadic in winter, Addison County is usually a stronghold for large flocks.

During the winter males are brownish with a striped back, but underneath these dark feather tips, the back feathers are solid black and the body feathers are pure white. He will wear down the feather tips by actively rubbing them on snow to become perfectly white and black for mating in the spring.

By early April males begin arriving back on the Arctic breeding grounds. Temperatures can still dip as low as -20 F with snow covering the ground. Males defend territories that include rocky areas used for nest sites, but they still forage and roost at night together in flocks of up to 80 birds. Females wisely delay their return for another six weeks.

Audubon recently examined population changes from the Christmas Bird Count. They found that snow bunting populations have declined 64 percent in the last 40 years. With an estimated global population of 29 million birds, the species is still common. But, 40 years ago there may have been as many as 40 million snow buntings in North America; now there are only an estimated 14.5 million.

The species’ main threat is most likely climate change in the breeding areas which causes earlier thawing of the tundra and allows more woody plants to grow. Snow buntings prefer relatively open sites, and these habitats are declining.

Other Bird Sightings

Christmas Bird Counts sponsored by Audubon have been in full swing across Vermont, producing some interesting sightings.

On Christmas Day a late osprey was sitting on a nesting platform and two lesser black-backed gulls were along the water at the Charlotte Ferry landing. Five mute swans were seen off Grand Isle. Introduced into North America from Europe to grace the ponds of parks and estates, escaped individuals have established breeding populations farther south, where their aggressive behavior threatens native waterfowl.

A golden eagle was flying south over Lake Champlain in Orwell on the 22^nd. A merlin was sighted in Addison on the 30th.

A male Barrow’s goldeneye was found north of the Champlain Bridge from the marina off Route 17on the 31st. This was among what is being called a “superflock” of thousands of other waterfowl, mostly common goldeneye and scaup, congregating on the lake. A late snow goose was spotted on Lake Champlain in Burlington on the 29th. A very late wood duck was seen in Woodstock on the 28th. Two ring-necked ducks were off Grand Isle on the 29th. Six red-breasted mergansers were seen off Grand Isle on the 26th. An American coot was spotted in Shelburne Bay on 28th.

Large flocks of Bohemian and cedar waxwings, pine grosbeaks, and common redpolls continue to be found across the state. Reports of the uncommon hoary redpoll have come from feeders in Waitsfield and Norwich.

Two late rusty blackbirds were observed at Button Bay on the 26th.

You can explore all the birds reported last week in Vermont and add your own sightings at Vermont eBird.

Kent McFarland