Monday, May 14, 2012

Rose-breasted Grosbeaks

Male Rose-breasted Grosbeak at Bodie Island lighthouse, NC, in April. © Dave Spier


Rose-breasted Grosbeaks -- © Dave Spier

One of our favorite birds returned from the south earlier this month. In fact, three of them were at the feeders at the same time, but we’re still waiting for a female which resembles an overgrown and overstuffed sparrow, but the males are a dramatic combination of black and white with outstanding rose-colored bibs, hence the name, Rose-breasted Grosbeak. The term grosbeak is a contraction of the words gross and beak with "gross" coming from an old French word meaning big or thick in reference to the stout, conical beak of these birds.

Female Rose-breasted Grosbeak banded by the late Bob McKinney, a long-time friend, at a previous Allegany Nature Pilgrimage (held annually on the first weekend after Memorial Day in southwestern New York).

Their primary food is seeds which they crack with that heavy bill. We often see them at our sunflower seed feeder. In the spring they also eat flower buds and I’ve photographed them in one of our cherry trees while the fruits were still totally green. During the summer they feed on small fruits and insects. I have one old report of grosbeaks eating young gypsy moth caterpillars as fast as they could catch them. They've also been observed catching cucumber beetles, canker worms, tent caterpillars, army worms, cut worms and cinch bugs. (Those so-called worms are actually caterpillars.) More power to these birds! If you want to plant some trees and shrubs to entice these birds, they seem to prefer the seeds, fruits and flower buds of serviceberry, elderberry, mulberry, dogwood, hawthorn and wild cherry. They also eat the seeds of beech, hickory, elm and maple.

One of "our" RBGR's singing in a cherry tree -- © Dave Spier


The male grosbeak's song has been likened to a robin after singing lessons. It is a slow, rich warble. The female also sings, but her version is softer and shorter. Their short call note, on the other hand, is more like a sneaker squeaking on the gym floor.

Rose-breasted Grosbeaks are said to favor open woodland and the edges of swamps and tree-lined streams. They’re a frequent visitor or resident at the Montezuma Audubon Center just north of Savannah, NY. Our yard has a lot of grown trees and, even though we're up on top of a drumlin hill, it appears to meet their needs. Hopefully they'll raise another family here like they did last summer. They build a rather flimsy nest and sometimes you can see the pale blue eggs through the bottom. The male helps incubate the eggs during the day, accounting for about 1/3 of the time on the nest. The female does the remainder and continues throughout the night. When not on the nest, the male is either standing guard nearby or bringing food to his mate. Another old report mentions carrying potato bugs to feed her on the nest. After fledging, young grosbeaks resemble the female and young males begin to show a tinge of pink in the fall. By this time, the adult male begins to lose his brilliance as he takes on buffier tones while his rose color turns to dull pink, making it easier for him to hide in the open tropical forest of the species’ winter range across Central America, Cuba, or the near reaches of South America.

Same male Rose-breasted Grosbeak at Bodie Island lighthouse, NC, in April. © Dave Spier

Your outdoor comments, corrections and questions are always welcome at northeastnaturalist@yahoo.com

Additional range information: The Rose-breasted Grosbeak, based on eBird reports, is found primarily north and east of the Great Plains with higher concentrations from the Mid-west and Great Lakes to New England and also northwestward across Canada to the Northwest Territories. During migration, it can be found anywhere east of the Rockies and across the South with a few sighted in the Western states. It spends the winter in Central and South America.
The website All About Birds contains a standardized range map:

2 comments:

mindfuldrawing.com said...

What a pretty bird. The male has great colours.

The Northeast Naturalist said...

Comment on Rose breasted Grosbeaks blogpost received from mindfuldrawing via email:


In the Netherlands we have the Kruisbek (Loxia curvirostra). It hasn't such bright colours as your male grosbeak but -of course- the same beak.
I've never seen one in the Netherlands nor anywhere else. I hope to see these birds soon. There is a beautiful old print on the Dutch wiki: http://nl.wikipedia.org/wiki/Kruisbek.

Paula

www.mindfuldrawing.com