Canvasback a regal member of duck family10:34 am | February 2, 2014
Some birds hold special significance.
One of my favorite birds is the Northern Cardinal. Among the warblers, the Hooded Warbler has long been my favorite. With shorebirds, the Marbled Godwit has long been at the top of my rankings. My favorite bird of prey is the American Kestrel. Among owls, I have a soft spot for Eastern Screech-owls.
I have a favorite duck, too. It’s not one that I see very often, which makes observations even more special.
I saw my first Canvasback in the mid 1990s during a visit with my parents to Wilbur Lake in the winter. We always liked visiting Wilbur during the colder months to view the Buffleheads and any other ducks that happened to visit this small mountain lake. On this particular occasion, a flock of Redheads had also arrived at the lake. While viewing the ducks, we noticed a member of the Redhead flock that looked different from the others. It was larger and whiter.
After a brief consultation with my copy of Roger Tory Peterson’s “A Field Guide to the Birds of Eastern and Central North America,” I identified my very first Canvasback.
I saw another Canvasback recently at the pond at Erwin Fishery Park in Unicoi County. The regal male Canvasbacks are unmistakable with a sloping profile that instantly distinguishes it from other ducks. Males, or drakes, have chestnut-red heads, white bodies, black breast and rear and bright red eyes. Their distinctive bill is also black. Females, like many other ducks, are drab and brown but share the distinctive bill, helping to separate them from such relatives as female Redheads.
The Canvasback is also a fairly large duck with males reaching a body length of 21 inches. Females are only an inch shorter in body length. Drake weigh an average of 2.7 pounds while hens can weigh 2.5 pounds.
The Canvasback breeds in prairie potholes in the western United States and Canada. I’ve not really seen that many Canvasbacks in Tennessee, but a trip to Utah in May of 2006 yielded unforgettable observations of large flocks of these impressive diving ducks. I found them in temporary ponds in flooded fields. The state had enjoyed abundant rainfall that spring, which was probably quite welcome by breeding ducks. The trip also yielded observations of such ducks as Cinnamon Teals, Redheads, Red-breasted Mergansers, Ring-necked Ducks and Gadwalls.
During winter, the Canvasback usually prefers large open bodies of water, including lakes, ponds and sheltered bays. I suspect the recent Arctic winter blasts have driven some of the local Canvasbacks to ponds like the one at Erwin Fishery Park. Canvasbacks have also been observed this winter at Osceola Island Recreation Area in the tailwaters of Holston Dam, as well as Musick’s Campground at South Holston Lake.
So, within the first month of 2014, I’ve been able to add Canvasback to my list of birds. Last year, when I really wanted to see this species, I could not find one.
Canvasbacks are largely vegetarian, although these ducks do consume some animal matter, including insect larvae, snails and other mollusks. This duck’s scientific name — Aythya valisineria— refers to a species of plant that Canvasbacks consume in great quantities. Vallisneria americana, which is often called wild celery or water-celery, doesn’t resemble the vegetable known as celery. These wild plants are long, limp and flat, which led to other common names such as “tape grass” and “eelgrass.”
The Canvasback is member of the genus, Aythya, which is comprised of a dozen species of diving ducks. The other members of the genus in North America include Greater Scaup, Lesser Scaup, Redhead and Ring-necked Duck. The Tufted Duck is a rare visitor to the United States.
Two members of the genus are endangered species.
The Madagascan Pochard was presumed extinct in the 1990s. In 2006, a small population of these ducks at Lake Matsaborimena in Madagascar brought the species back from extinction. In March of last year, a survey found the population of this duck is about 80 individuals. The Madagascan Pochard is also included on the list, The World’s 100 Most Threatened Species, which is a compilation of the most threatened animals, plants and fungi published by the Zoological Society of London.
Baer’s Pochard — named for Estonian naturalist Karl Ernst von Baer (1792-1876) — is another endangered species in this genus. Baer’s Pochard ranges throughout eastern Asia, breeding in southeast Russia and northeast China and migrating during the winter months to southern China, Vietnam, Japan and India. In the early 1900s, naturalists described this duck as abundant and common. By 1990, however, fewer of these birds were being seen on their wintering ground each year. In 2008, it was officially listed as endangered. When surveys found a worldwide population of perhaps fewer than 1,000 individuals, Baer’s Pochard was reclassified as Critically Endangered in 2012.
The Canvasback has never declined to the low levels of these relatives, but it has been a bird that has required some protective oversight from the federal government. At times, this has included exemptions from duck hunting seasons.
Canvasback populations are stronger these days, but they haven’t been robust for quite some time. According to the Duck Unlimited website, the population of this stately duck has seen some improvement. In 2009, a population survey by the U.S. Department of Fish and Wildlife showed an increase in Canvasbacks from 488,000 to 662,000 individuals. According to the Ducks Unlimited website, this population spike took place in the wake of a hunting ban on Canvasbacks during the 2008-09 waterfowl season.
Johnson City resident Alf Peoples observed hundreds of American Robins at his West Carter County home on Jan. 23. He said the trees around his home were filled with at least 500 robins. Robins have been abundant in the region this winter. Perhaps, since these recent frigid temperatures have affected almost the entire eastern United States, the robins didn’t see much point in migrating farther south.
I saw a large flock of robins strip the berries off a large holly tree in the parking lot at Tetrick’s Funeral Home in Elizabethton. In less than a couple of days, the birds left this large tree with almost no berries. In their haste to strip the fruit from the branches, the birds also dropped a lot of the berries onto the parking lot, blanketing the asphalt with a layer of the bright red berries.
I’ll be presenting a slide show on local birds during the annual Roan Mountain Winter Naturalists Rally on Saturday, Feb. 15. The program will be presented during the rally’s noon lunch break. Naturally, I’ll focus mostly on birds that can be found on Roan Mountain, but I’ll probably include some other favorite bird photos, too. In addition, Lisa Huff with the Tennessee Natural Areas Program will provide an update on efforts to curb invasive plants on Roan Mountain. For more information on the rally, call Director David Hall at 772-3500 or email him at email@example.com.
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