Yellow-headed Blackbird

Feeding Behavior

Forages mostly by walking on the ground in open fields or near the water's edge; also forages low in marsh vegetation. Sometimes catches insects in flight. May follow farm machinery in fields to feed on insects and grubs turned up by the plow. Except in nesting season, usually forages in flocks, often associated with other blackbirds.

Eggs

4, sometimes 3-5. Pale gray to pale green, blotched and dotted with brown or gray. Incubation is by female only, 11-13 days. Young: Both parents feed nestlings. Young leave nest after about 9-12 days, but remain among dense marsh plants until they are ready to fly, about 3 weeks after hatching. 1 brood per year, possibly 2.

Young

Both parents feed nestlings. Young leave nest after about 9-12 days, but remain among dense marsh plants until they are ready to fly, about 3 weeks after hatching. 1 brood per year, possibly 2.

Diet

Mostly insects and seeds. Feeds heavily on insects in summer, especially beetles, caterpillars, and grasshoppers, also ants, wasps, and others, plus a few spiders and snails. Young are fed mostly insects. Probably two-thirds of diet consists of seeds, including grass and weed seeds plus waste grain.

Nesting

Typically nests in colonies in marshes, each male selecting territory within colony and defending it against rivals by singing. One male may have as many as 5 mates. Nest: Placed in marsh, firmly lashed to standing vegetation (cattails, bulrushes, reeds) growing in water, usually no more than 3' above water's surface. Nest (built by female) is a bulky, deep cup woven of aquatic plants, lined with dry grass or with fine, dry marsh plants.