|10/14/2010 1:36:00 PM|
by Don ReimerOccasionally I submit a Name-That-Bird photo challenge for readers to study and identify. Even within a given species there can be noticeable variations in color and plumage characteristics due to age or sex of the bird and seasonal variations. In short, birds do not always precisely match the drawings or photos in birding field guides. Foliage or other obstructions may also prevent a clear satisfying view of a bird.
Today's quiz bird is medium-sized (about the size of a robin) with a stout yellow-green bill that is partially obscured by foliage. The bird's body is uniformly olive green and the wings and tail are black. There is a hint of yellow on the throat and under the tail. During the summer nesting season, this neotropical species nests high in the upper canopies of mature deciduous or mixed forest in the eastern U.S.
The reader would benefit from knowing that the quiz bird is currently in its dull winter plumage that is extremely different from its bright summer breeding feathers.
Ready? Here comes the answer:
The quiz bird is a male Scarlet Tanager found on Monhegan Island in late September. From March through August, male Scarlet Tanagers are indeed a brilliant scarlet-red of almost fluorescent intensity; from September through the winter season, however, they are a flat green color. The greenish females remain green throughout the year. Partially molted fall males are often an interesting mix of blotchy red and green feathers.
The Scarlet Tanager is the only tanager species to undergo seasonal plumage changes. In late May, the female Scarlet builds a treetop nest of fine twigs while the male keeps a low profile nearby to prevent predators or nest parasites, such as the Brown-headed Cowbird, from discovering the nest construction. Each nest has an overhanging cluster of leaves that shade and camouflage the location. Despite their bright red plumage, male Scarlet Tanagers can be very difficult to spot in their summer treetop domain.
Male tanagers court their mate with a hoarse warbling song commonly described as similar to "a robin with a sore throat." Females respond with a softer, shorter version of the song that helps to keep the pair in contact.
These tanagers eat a diet of insects, spiders, seeds and berries. It has been estimated that a single tanager once consumed a total of 2000 gypsy moths within a one-hour period. Insects are gleaned from the forest foliage and "hawked" from the air in flycatcher fashion. During migration to South America, tanagers seek out thick cover that is rich in berries, grapes and other fruits. Many falls ago I observed a group of several tanagers feeding in a tangled grape vineyard. A collective group of such tanagers is known as a "season of tanagers."
On their tropical wintering grounds, Scarlet Tanagers forage among mixed flocks of birds, including a variety of flycatchers, antbirds and woodcreepers. Tanagers are actually related to the cardinal family. At times Maine birders may encounter the more southerly-breeding Summer Tanagers or, more rarely, a colorful vagrant Western Tanager.
Article Comment Submission Form