By Kenneth Turner Blackshaw
There is an old joke about a cow that swallowed some blue dye. After that, whenever she opened her mouth, she "Moooo'd Indigo". Well, along about mid-April every year, Nantucket's birders get into an indigo mood -- an Indigo Bunting mood that is -- and start scouring the back lawns of 'Sconset looking for anything blue.
We drive or walk through Nantucket's east end hamlet many times. Now and then we are lucky and these little blue gems pop out. In 2002, Nonie Slavitz not only found an Indigo, she also found a close relative, the Lazuli Bunting. Lazulis are Rocky Mountain birds and this was the first record for Massachusetts. The birds were enjoying a wonderful mud puddle on Chapel Street. Since then, that area has been 'gentrified'. The drive has been bricked and a storm drain added. Hence, no puddle. So goes Nantucket.
Indigos are tiny, almost as small as a goldfinch. The males are easily described, being a brilliant indigo blue about the head, neck, and breast, which fades to a slightly less intense color further back on the bird. Unfortunately, blue can be a tough color, requiring strong illumination. So, strangely enough, unless there is good light, these brilliant blue birds often appear black.
The females are another story. Indeed, they are a perfect example of nondescriptness. Roger Tory Peterson describes them as "the only small brown finch devoid of obvious stripings, wingbars, or other distinctive marks." Often birds arriving here on Nantucket are mottled males, still changing from winter browns to spring indigos. So you get some weird combinations of blue and brown. Although there must be as many females as males, you seldom see them.
Since buntings are finches, you might think they feed almost exclusively on seeds. But, hopping around on the ground, they also feed on a lot of grasshoppers, caterpillars, measuring worms, and beetles. They seldom venture up onto a feeder.
Most Indigo Buntings are true neotropical migrants. That is they winter in the new world tropics of this hemisphere, all but a few of them forsaking the shores of the U.S. So, when we meet one of these little drops of azure on a green lawn, it has flown a long way, and seen many other climes since being up north last year. Some of them fly across the Gulf of Mexico to the Yucatan. Others take the land route through Texas. Banding records show they can make the journey from the Yucatan Peninsula, up into Maine in 36 hours!
Indigo Buntings are a common summer bird through most of the eastern U.S. If you learn their spirited "fire fire, where where, here here" song, which is whistled about eight times a minute from a prominent perch, you will easily locate them.
Having said that -- they have never been found to nest on Nantucket. So apparently they don't like the salt air and head off-island. Some years, the spring migrants even miss us. Other years, like this one, they show up in many places -- Miacomet Avenue; Lincoln Circle; Monomoy. Are they in 'Sconset too?
At the time she wrote her 1948 book, Edith Folger Andrews had only seen this species once on the island. Now, Birding Nantucket shows it to be uncommon in spring and fall, and rare through the end of December. It has only been recorded once on our Christmas Bird Counts -- in 1978.
If you leave the island and move away from the shore, look and listen for them along forest edges and brushy roadsides. Typically, their nests are placed in crotches of shrubs or saplings only a few feet from the ground in dense cover. The European's clearing of the forest canopy for agriculture has benefited this species. It has also benefited one of their main enemies, the Brown-headed Cowbird, which lays its eggs in other bird's nests. The cowbirds hatch earlier, grow more quickly, and drive out the rightful residents. So, the buntings have benefited and also been harmed. Still they are thriving.
So if you are in an indigo mood, now is the time to look for them. When they return in the fall, they will be brown, and the mood will have passed.
George C. West creates illustrations for these articles.
Next Saturday, the 8th, is International Migratory Bird Day. There will be a special program and walks in 'Sconset, starting from the Fire Station at 8 a.m. Call Edie Ray at 228-1693 for more information.
If you enjoy social birding, every Sunday a group meets in the parking lot in front of the Nantucket High School at 8 a.m.
To hear about rare birds, or to leave a bird report call the Massachusetts Audubon hot line at 888-224-6444, option 4.