BIRDS OF NANTUCKET
by Kenneth Turner Blackshaw

White-crowned Sparrow

AN ARISTOCRATIC LBJ

At this time of year there are many little brown jobs (LBJs) passing through Nantucket. Sparrows, wrens, and thrushes fall into this category. Depending on what the weather did during the night, you can step outside at dawn and hear a different concert every morning. The other morning it was towhees, this morning it was White-throated Sparrows and juncos. But only very rarely will it be this week's bird, the aristocrat of the LBJs, the White-crowned Sparrow.

The Latin name is a mouthful, Zonotrichia leucophrys. The name, provided by the English naturalist and friend of Audubon, William Swainson, means 'banded thrush,' and must have been given based on rather poor details. Swainson went on to become Attorney General of New Zealand. Although he never traveled to North America, we have a warbler, a hawk, and a thrush named for him.

Aristocratic? Well, these sparrows are still brown - mainly. I guess it's their appearance and carriage that make viewers feel they are special. White-crowns are slightly larger than most sparrows, seven inches from beak to tail. The beak is distinctive. Still a conical finch-type of beak, but pink, standing out from the rest of the bird.

And, wonder of wonders, the bird is well named, for it does have a white crown. Depending on its level of excitement, the headgear may look like a black and white football helmet, or perhaps like a centurion's headgear. White-crowned Sparrows also stand tall most of the time, often craning their neck to see what is going on. The black and white striped head stands out above the soft gray neck.

Now I must confess I've told a little fib. For although adult White-crowns are well-named, it is mainly the first year birds we find here on our island. So instead of the brilliant black and white striping on the head, we see reddish brown and tan. Not until late in April do the blacks and whites appear.

But the rest of the plumage is similar and so is the aristocratic carriage. So the column's title is still okay. Perhaps even more so since these young birds on their first year's journey are even more LBJs than their parents.

When they reach Nantucket, they've already come a long way. White-crowns nest beyond the northern forest in the sub-alpine and tundra regions across northern Canada. So far north are they that most of the nests are built on the mossy ground, beneath what little cover that can be found. It is also an area with 24 hours of sunlight and the males proclaim their territory by singing around the clock for several weeks.

Both parents share the chick-raising duties that are quite arduous in that far northern climate. Unlike many birds nesting at that latitude, Whitecrowned Sparrow chicks are altricial, the opposite of precocial, hatched naked and blind and unable to even call for the first five days of life. The youngster are fed mostly insects, the Arctic being full of those creatures in the short summer. But most of the year, White-crowns are seedeaters like the rest of the finch tribe.

This characteristic makes it easy for bird banders to trap them and thus they have become one of the most studied of North American birds. Nantucket is at the northern edge of their winter range that extends all across the southern U.S. and into Mexico. Our 50 years of Christmas Bird Count data shows them becoming more regular early winter residents here, with a high count of 17 in 1998. If you go to view the Maria Mitchell bird collection you'll find two of them from 1958.

In addition to learning where birds go, banding data also helps us learn how long they live. There are a few White-crowned Sparrows that have lived longer than eight years, a long time for a small songbird. As I mentioned before, most of the ones we see here are trying to get through their first year. Apparently many are not successful. Most Whitecrowns that age to the point of actually wearing their black and white striped crowns do so by not venturing so close to the briny deep.

So when Nantucket birders find a Whitecrowned Sparrow it is cause for celebration. We are always charmed by their aristocratic appearance and we also realize that the birds that arrive here have made a special sacrifice. Unlike humans, most only

make one trip to Nantucket in their lifetimes. 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: kenandcindy@ copper.net.