General Information

The Yellow-headed Blackbird is a medium-sized bird with a breeding and migratory range that span from the United States into Mexico.  It is known to have a low raspy song that ends in a descending buzz, and sounds like the grating of a rusty hinge.  Outside of the breeding season, Yellow-headed Blackbirds can be found in flocks, often with other blackbird species.  During the winter, single-species flocks are known to form, sometimes of only males and other times of only females.

Physical Description

This bird has an unmistakable appearance. It has a bright yellow head and chest with a black mask around its eyes.  Black covers the rest of its body (including legs) except for white wing patches most conspicuous in flight.  In general, they are 8 – 10 inches long and weigh up to 100 g.  The female is considerably smaller than the male, and is mainly brown with a dull yellow throat and breast.  Females also lack the white wing patches.

Diet

Their diets vary through the year.  During the spring and summer, when they feed their young, these birds consume many insects.  During the fall and winter they feed on seeds and waste grains.  Annually, 2/3 of their diet is seeds and grain.

Habitat

The Yellow-headed Blackbird’s breeding habitat is cattail marshes located primarily west of the Great Lakes.  During the winter, they migrate to the American Southwest and Mexico.  In the United States, they occur permanently in the San Joaquin Valley of California and the Lower Colorado River Valley of Arizona and California.  They can be found in marshes, and, especially during the non-breeding season, open fields.  In marsh areas where they occur with smaller Red-winged Blackbirds, the Yellow-headed tends to occupy the center of the marsh while the Red-winged inhabit the periphery.  These birds nest in colonies, with nests built with and attached to marsh vegetation, and suspended 1.5 – 3 feet above water.

Reproduction

These birds are polygamous.  A male may have up to 6 mates, although 2 – 3 are more common.  They breed in colonies, where a single pairing lasts for a single breeding season.  A female lays 3 - 5 eggs per clutch and incubates them for about 11 – 13 days.  After hatching, the female will brood the young for a few days, providing most of the food.  The male may also help feed.  It is typical for females to raise one brood per season, but sometimes may raise two.  The young leave after 9 – 12 days.  They stay within close vicinity of the nest for another 9 – 12 days, until they can fly.  After fledging, the young are still fed by the mother for a few more days.