A blackbird that sounds like a rusty farm gate opening

Recently while on a photo field trip I came across a flock of birds by the Kootenai National Wildlife Refuge. The birds in a flock of about 50 had golden heads, a white patch on black wings, and a call that sounded like a rusty farm gate opening, the yellow-headed blackbird demands your attention. They were an impressive flock as the group seemed to roll across the wetlands and field beside the road. Each bird would glean seeds from the ground, and then leapfrog over its flock mates to the front edge of the ever-advancing troupe.

Look for them in western and prairie wetlands, where they nest in reeds directly over the water. The male yellow-headed blackbird is impressive to see, but not to hear. It may have the worst song of any North American bird: a hoarse, harsh scraping. The female is a large brown bird with a dull yellow head, chest and nape of neck, black mask, gray bill, and white wing patches. Yellow-heads nest in noisy colonies in big cattail marshes of the west and Midwest; when not nesting, they gather in flocks in open fields, often with other blackbirds. At some favored points in the southwest United States in winter, they may be seen in flocks of thousands.

The yellow-headed blackbird often nests in the same marsh as the red-winged blackbird. The larger yellow-headed blackbird is dominant to the red-winged blackbird, and displaces the smaller blackbird from the prime nesting spots. The yellow-headed blackbird is strongly aggressive toward marsh wrens too, probably because of the egg-destroying habits of the wrens.

Yellow-headed Blackbirds eat mostly insects in summer and seeds the rest of the year. They catch aquatic insects at the water’s surface, including beetles, grasshoppers, dragonflies, caterpillars, flies, ants, and spiders. Outside of the breeding season they forage in uplands eating grains and weed seeds. They form “rolling” flocks in farm fields, with individuals continually taking flight at the rear of the flock and landing at the front lines to feed. After establishing a foraging site, a flock will return to the same area repeatedly for several days. The blackbirds probe into soft ground and spread their bills to open up leaf sheaths or enlarge holes. They also flip over stones to unearth food.

The female builds the nest by herself. She weaves long strands of wet vegetation, collected from the surface of the water, around 4-5 upright stems. She adds more strands and more supports, and then an outer wall and an inner cup of the same materials. The outside of the nest is 5-6 inches across and about the same height, while the inside measures about 3 inches across and 2.5 inches deep.

The female chooses a nest site within a male’s territory always picking a spot that overhangs the water. She affixes the nest to live or dead vegetation—usually cattails or reeds. The clutch size is 2-5 eggs with only 1 or 2 broods per year, and the incubation period is 12-13 days. The nesting period is 7-14 days, with the newborn hatching helpless and eyes closed. Nestlings have pink skin covered with patches of tawny down, and their mouths are bright red and pink. Because yellow-headed blackbirds build their nests over the water, nestlings sometimes fall in and have to swim short distances to vegetation and safety.

The oldest yellow-headed blackbird on record was at least 11 years, eight months old. It had been banded in Saskatchewan and was found in Nebraska. They migrate to the southern United States or to Mexico. They generally migrate in flocks of up to 200 with other blackbirds. Most colonies consist of 20 to 100 nests.

Enjoy the outdoor beauty of Boundary County.

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