“A Year of Birding in Bloedel” is a column that runs every Friday in the Bainbridge Islander. The project is planned to continue in 52 parts through 2014 to help readers find and identify birds in the island’s garden sanctuary. Beginning with this entry on the bald eagle, each column will also be published here on the Bainbridge Conversation blog each Friday.
The author, Ted Anderson, is a retired professor of biology, having taught at McKendree University (Ill.) for 32 years and for the University of Michigan’s summer biological station for 20 years, where he frequently taught the biology of birds.
Anderson is also the author of “Biology of the Ubiquitous House Sparrow, from Genes to Populations” (2006), and “The Life of David Lack, Father of Evolutionary Ecology” (2013). Ted and his wife Carol have been members of Bloedel Reserve for seven years. They live in Kingston.
Mid-May brings the Black-Headed Grosbeak (Pheucticus melanocephalus) back to the Pacific Northwest from its wintering grounds in southern Mexico and Central America.
The melodious song of this denizen of forested habitats throughout the western states resembles the song of the American Robin, but is usually longer and is often punctuated by a “chunk” note that is typical of the species. The song is virtually identical to that of its close cousin, the Rose-Breasted Grosbeak, that replaces the Black-Headed Grosbeak in eastern North America.
Black-Headed Grosbeaks are sexually dimorphic with adult males, as their name implies, having a black head as well as black upper back, wings and tail. The underparts and rump are a rich cinnamon brown and the wings have prominent white spots. Females and first-year males have brownish upperparts and yellowish-orange underparts, and a white stripe over the eye. Both sexes flash large yellow patches under their wings when they fly.
In most songbirds only the male sings, but grosbeaks are an exception.
Females regularly sing a song similar to that of males, but less complex. Both sexes also participate equally in breeding activities, and both male and female may actually sing from the nest while incubating the eggs. The nest is usually located in the outer branches of a deciduous tree or shrub.
The large conical beak of grosbeaks enables them to husk large seeds, and they are frequent consumers of quantities of sunflower seeds at backyard bird-feeders. About half of their diet is insects, however, particularly during the breeding season. They typically forage high in deciduous trees gleaning insects from the foliage.
One interesting feature of grosbeak foraging is that they have adapted to eating Monarch butterflies, which are toxic for most birds, in their enormous winter congregations in the mountains of Mexico. The result can be a orange carpet of Monarch sings under the trees where they congregate to spend the winter.
At Bloedel, listen for their melodious song as you walk along the forested paths, and search the upper branches for a glimpse of this strikingly-plumaged songster.