Saturday, April 21, 2007

Another Rarity Visits Windham County

Two weeks ago another rare waterfowl was found along the lower Connecticut River. Maybe. When the male Eurasian Green-winged Teal flew from New Hampshire’s Connecticut River into Vermont’s Herrick’s Cove it may have created a first record for Vermont for this duck. Or it may have just been another Green-winged Teal.

First some background on the Green-winged Teal. This teal is our smallest dabbling duck. Dabbling ducks feed by turning themselves upside-down in order to feed on plant life beneath the water’s surface. Mallards, American Black Ducks, and Northern Pintails are among the most familiar “dabblers.” Canada Geese, though not ducks, are dabblers. The Green-winged Teal has a length of 14 inches and weight of 12 ounces. Only the Bufflehead, a diving duck, is smaller (L. 13.5 inches). The teal is slightly larger than the Rock Pigeon (L. 12.5 inches, W. 9 ounces), and significantly smaller than the American Crow (L. 17.5 inches, W. 1 pound), although comparing a duck with a song bird is like comparing apples and pears.

The Green-winged Teal, like most waterfowl, is most often observed on swimming on water, and usually with other ducks, usually at a distance, and usually through binoculars or a scope. All of these conditions make it difficult to wrap the mind around its small size. Several years ago in southern Texas during the winter, I walked along a boardwalk in a marshy refuge. Green-winged Teal were feeding in the water below us, not fifteen feet away. I still remember clearly our reaction: “They’re so tiny!”

Green-winged Teal are common and widespread. A few weeks ago when the night roost for migrating waterfowl was just above the Vernon dam, Canada Geese were the most common with an estimated 4000 geese present. The next most common waterfowl was the Green-winged Teal whose numbers were around 500.

This small duck breeds near shallow freshwater lakes and marshes from Alaska, across all of Canada, in the northern Great Plains, and along the St. Lawrence valley. It winters widely throughout the south and west.

The name comes from the bright green speculum on the secondary wing feathers. This green patch is notable when the bird is in flight, and is usually visible when afloat. Apart from the noticeable “green-wing,” the hen is a plain, brown duck with few distinguishing characteristics.

The drake Green-winged Teal, on the other hand, is a stunningly handsome bird. Uppertail coverts are a rich yellow, visible at a distance and giving away its identity when dabbling in its upended manner. Overall, its wings and body are gray, but dappled with pattern; tail feathers are black. The head is a rich, ruddy brown with a broad green strip running from the eye to the neck. A vertical white slash between the breast and sides is a distinguishing mark even at a distance and in poor light when other characteristics are to see.

Hold on to that vision of the vertical white slash as I return to the Eurasian Green-winged Teal which was in Herrick’s Cove last week. This bird did not have the vertical white slash. Instead, it had a bold horizontal white stripe running along the side of its body - or more specifically, a white stripe on the scapulars of the wing. In other respects, it was identical to the teals it was feeding with, and with which it was competing in display before the hens. Even at a distance of a couple hundred yards and through a scope, the white horizontal stripe was prominent. There were two recognizably different teals present.

But now we must move from the relatively straightforward recognition of differing field characteristics to the murkier world of taxonomy - of identifying and acknowledging species.

In Europe, this bird has been known as the Common Teal, and more recently has been renamed the Eurasian Teal. If I were a visiting birder from Great Britain or the Netherlands and had seen the teals in Herrick’s cove last week, I would have listed two birds for my North American list. I would have listed the Eurasian Teal (Anas crecca) and Green-winged Teal (Anas carolinensis). Under the prodding of the Association of European Rarities Committee, all of Europe recognizes these two species.

Not so on our side of the pond. The American Ornithological Union (AOU), which determines taxonomy, has refused to take up the split of this (or these) teal(s). The American Birding Association (ABA), which determines the official bird list for the North American birders who compete for who has the biggest list, has kept lock-step with the AOU.

Consequently, as a North American birder, when I peered across the mud bar at the teals feeding upended, and specifically at the drakes showing off for the hens, I was looking at one species represented by two races. I was looking at Green-winged Teals (Anas crecca carolinensis), our common North American sub-species. And I was looking at a single Eurasian (or Common) Teal (Anas crecca crecca), a sub-species common to Europe and Asia, which somehow wandered out of its normal range.

I am sure you see the disconnect as readily as I do. It is so tempting to have fun with this American isolationism from the rest of the world. Such as - here’s another example of the bad science of the current administration - another “we know more than anyone else in the whole wide world.”

But when you come right down to it, it only matters to a few high testosterone birders and cloistered taxonomists - those who want to have a big and controlled list and those who are the most superior scientists.

It doesn’t matter if I count one species or two species, because I don’t need to show my list to you and I don’t have any need to see yours. What matters is having fun out-of-doors. Watching the birds. Sometimes pursuing a rarity. Enjoying their displays. Appreciating their beauty. Tracking the comings and goings. Having fun.

That’s good birding.

1 comment:

Julie in VT said...

"That's good birding."




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