BIRDS OF NANTUCKET
A bird with a rash
by Kenneth Turner Blackshaw
T o my dear grandmother, 'Nana' Grace Turner, these were all 'wild canaries.' We had a perfectly wonderful 'tame' canary that sang his little heart out from his cage in the parlor so I was excited with the idea there could be wild ones on our island. Perhaps, it led me into a study of birds that has brightened my whole life. Later on, I discovered that my Nana's definition of wild canaries included any feathered yellow thing that might zip by, be it a goldfinch or on e of ou r co lorful wo od warblers. Our canary in its cage was unique!

Our 'wild canary' this week is a wood warbler and really the most yellow bird you are likely to see. Its name is the Yellow Warbler, Dendroica petachia, translating to tree dweller with a rash. It is yellow all over, even the wings and tail. On the back, the yellow has a greenish tinge. Oh! And there are orange streaks down the male's belly - the rash mentioned above.

This bird is a true neo-tropical migrant. All Yellow Warblers leave our borders for Central and South America every year. Almost all Nantucket's fly across the Gulf of Mexico to the Yucatan and back annually. This is an amazing trip for a delicate appearing bird weighing three-tenths of an ounce.

Our Yellow Warblers have been with us since the first days of May. The best way to be aware of them is to know their song - a whistled 'sweetsweet sweet-I-am-so sweet.' This is repeated three times a minute and can be heard any time of the day. They are not unhappy hanging out near human habitation. A walk along the first se ction of the Madaket bike path yielded 11 singers the other morning.

So hearing is one thing - what about seeing? Sometimes they'll be on the tip top of a bush, but just as likely they'll be hidden within. Birders like to 'pish' them out. Make a sound like you are shushing someone only put a 'p' at the beginning. Repeat this rapidly and you'll be surprised at the results. The key is watching for movement, not too hard on a calm day but tricky when it is windy. Often you see just a head or a tail, but be patient.

Right now Nantucket's Yellow Warblers are in the middle of raising their families. They lay four or five eg gs and it takes 11 days for them to hatch. Mrs. Yellow Warbler is just slightly paler than her mate and does all the incubation, covering the eggs on chilly mornings, making a rain shield when it is wet and standing like a yellow parasol with wings spread if it is too warm.

The main enemy of these rashy birds is the Brown-headed Cowbird. You may remember that cowbirds build no nest of their own, preferring to take advantage of the generosity of their neighbors. If incubation has already started, Yellow Warblers frequently become unwitting foster parents. If the interlopers are discovered before the clutch is complete, the homeowners will build a new nest right atop the old one. Yellow Warbler nests have been found with as many as five st ories.

The real problem is that the cowbird eggs hatch more quickly. The cowbird chicks become larger and compete for food more vigorously and consequently the Yellow Warbler chicks are quite often starved out. Nature is complicated and sometimes it seems like the bad guys win.

On the other hand Yellow Warblers are considered exemplary citizens in that their diet is almost completely insectivorous. This is why you never find th em at yo ur bi rd fe eders, un less you put out some mealworms. You may have these wild canaries around your yard and be unaware of it until you learn their song. However during dry spells your birdbath could attract them.

Just as an aside, a birdbath is a wonderful asset. During periods of regular rain it will stay full but if you notice it drying out that is your clue that the birds around you may be drying out as well. Be sure and top off that birdbath and maybe a Yellow Warbler will visit you.

Our birds with a rash are itching to leave us by the end of July. They are among the earliest fall migrants and indeed some early travelers have been found in Central America as early as August 9. They continue to pass through Nantucket through the month of September. During that month we watch for greener ones, part of the Alaskan race. Yellow Warblers nest from coast to coast across North America, even to the Arctic shores.

Although we consider them our birds, the people in Guatemala, where so many of them winter, also consider them theirs. Indeed they spend eight or nine months down south and only three or four up here. That is why the dramatic clearing of habitat in Central America is having a very detrimental effect on the population of birds like this warbler. You can fight this trend by drinking only 'shade grown' coffee. Nantucket Coffee Roasters can provide you with this type of coffee that is quite delicious. It costs a little more, but if enough of us make a statement, perhaps we can reduce the threat to this colorful gem's winter home. I

George C. West creates illustrations for these articles.

The Maria Mitchell Association sponsors bird walks on Tuesday and Thursday mornings at 6:30 a.m. and Saturday mornings starting at 8 a.m., from the corner of Vestal and Milk streets. There is a fee for non-members.

To hear about rare birds, or to leave a bird report call the Massachusetts Audubon hot line at 1-781-259-8805.

Find more about Birding Nantucket on the web at http://k-blackshaw.com/BN/ BN.htm