BIRDS OF NANTUCKET
by Kenneth Turner Blackshaw
SELECTING JUST THE RIGHT SHADE OF GREY What a charming surprise this duck is. If you follow Yogi Berra’s wise expression, “You can observe a lot just by watching,” it provides a great tool for finding them. A few days ago, the Sunday morning social birders were looking at a group of Black Ducks in one of the ponds in the Cricks. I was hoping we’d find a Northern Shoveler but the dark grey bill on one of the ducks caused me to give it special attention.

North American Gadwall

At first glance, this might sound like a classic example of ‘boring’ birding. I mean, these were just a bunch of brown ducks. But once the birding bug bites you, even brown birds become interesting. Heck, they can fly. They can do all kinds of things about which we can only dream. So as we look at a flock of brown ducks many things go through our minds. Are they feeding? If so, on what? Are they males or females? Are they paired off? Are they looking nervous? Have they been hunted recently? Let’s face it, if you’ve been subjected to gunfire and seen close friends or relatives killed or knocked from the sky, never to fly again, it can make you skittish.

Generally, the first challenge is just to ID them. Quite often there are Mallards mixed in with a flock of Black Ducks, even genetically speaking since they interbreed. Distinguishing duck females can be tricky since many of them are speckled brown ducks. Often the best technique is seeing which drakes they are consorting with.

Duck species can also be divided into two major categories — those that dive and those that dabble. Dabbling means they tip forward, head down in the water with the rear end sticking vertically upwards, and reach down to grasp vegetation growing from the bottom. By their shape and behavior we could see these ducks were dabblers.

On Nantucket in early winter it’s also important to know the cast of characters. What species of dabblers are likely? Mallards and Black Ducks are the most common, followed by American Wigeon, seldom seen in the Cricks. After that, perhaps Greenwinged Teal, or a Northern Pintail. This week’s bird, the Gadwall, falls in this category.

The duck’s Latin name does little to make it stand out, Anas strepura, translates to a ‘noisy’ duck. Hard to understand the reasoning. They are ducks, but not particularly noisy. But then, this was one of the ‘early birds’ named by the Swedish naturalist, Carl Linnaeus, in the mid-eighteenth century. Since this duck lives all around the Northern Hemisphere, not just in North America, it was named early in the development of the scientific ‘binomial’ naming system. They nest around Stockholm so perhaps Carl found them noisy in the breeding season.

Anyway, after noting the dark grey beak it quickly became apparent that the rest of the duck was different as well. Adrake Gadwall has a smooth gray appearance, rather than speckled brown. Also the stern is jet black. As Edith Andrews observes, “They have black velvet rear ends!”

In flight, another mark shows up, a white square on the trailing edge of the inner wing, in an area birders know as the secondary feathers. The long flight feathers at the end of the wing are primaries. Both Mr. and Mrs. Gadwall show that white

patch in flight, but with the wing folded it is often

hidden. In this case there was a pair of them and we could note the subtle differences between the female Gadwall and other ducks nearby.

It seems that Gadwalls are a recent introduction to Nantucket. Completely missing from Griscom and Folger’s 1948 “Birds of Nantucket,” the first occurrence I find is as a ‘count week’ bird on the 1957 Christmas Bird Count (CBC). Since 1975 they’ve been found on most every CBC with a high of 28 in 2003. “Birding Nantucket” lists

them as “uncommon” from December through

February and then rare for a month or so on either side of that.

Although we don’t expect them here in summer they were introduced on the Vineyard in 1971 and there have been two to four pairs nesting there ever since. The record for the oldest Gadwall is just under 20 years, but in the wild most of them don’t see ten. So the Vineyard population is probably three or four duck generations old.

Most North American Gadwalls nest in Saskatchewan in western Canada. There they are one of the most common nesting ducks. They’ve never been common here, but then, they blend in. Finding a Gadwall on Nantucket is like finding one grey house that stands out from the rest. It’s a tricky

task, but very rewarding. I

George C. West creates illustrations for these articles. If you enjoy ‘social’ birding, join the Nantucket Bird Club at 8 a.m. Sundays in front of Nantucket High School for a two to three hour birding trip. Call 228-1693 for more information. To hear about rare birds, or to leave a bird report call the Massachusetts Audubon hot line at 1-781-259- 8805.

Ask Ken a question at: kenandcindy1@comcast. net.