Yellow-headed blackbird

Xanthocephalus xanthocephalus

Photo by Mike Ross (Internet Bird Collection)

Common name:
yellow-headed blackbird (en); graúna-de-cabeça-amarela (pt); carouge à tête jaune (fr); tordo cabeciamarillo (es); brillenstärling (de)

Taxonomy:
Order Passeriformes
Family Icteridae

Range:
This species breeds in south-western Canada, in eastern British Columbia, Alberta, southern Saskatchewan, southern Manitoba and marginally in south-western Ontario, and in the United States, mainly east of the Cascades, from Washington to Michigan and south-westwards into to north-western Texas, northern New Mexico, northern Arizona and some areas in southern California. Also marginally into Baja California, in Mexico. They migrate south to winter from southern Arizona and Texas to central Mexico as far south as Puebla.

Size:
These birds are 21-26,5 cm long and have a wingspan of 42-44 cm. Females are smaller than males, weighing 44-60 g while males can weigh up to 100 g.

Habitat:
the yellow-headed blackbird is mostly found breeding in wetlands with abundant emergent vegetation, such as marshes, swamps and bogs, but also use grasslands and parks located near wetlands. Outside the breeding season they also use arable land and pastures. They are present from sea level up to an altitude of 1.000 m.

Diet:
During the breeding season they feed mainly on aquatic insects, but also other insects, including beetles, grasshoppers, dragonflies, caterpillars, flies and ants, as well as spiders. Outside the breeding season they feed on grains and weed seeds.

Breeding:
Yellow-headed blackbirds breed in May-June. They are polygynous, with males defending harems of up to 16 females. Each female builds one nest, a cup made of woven strands of wet vegetation, attached to the leaves of aquatic plants and always located above water. There she lays 2-5 greyish to greenish-white eggs with brown, rufous and grey blotches, which she incubates alone for 11-13 days. The chicks are fed by both parents, although the more females the male has in its harem the less it is involved in feeding the young. They fledge 9-14 days after hatching.

Conservation:
IUCN status - LC (Least Concern)
This species has a very large breeding range and the global population is estimated at 11 million individuals. The population has undergone a small increase over the last 4 decades, possibly due to the increase in food supply for the birds outside of the breeding season caused by the expansion of corn, sunflower and small grain production. They may be affected by wetland drainage and their diet and habitat choice can expose them to herbicides and pesticides. In some areas, farmers consider yellow-headed blackbirds a pest and use toxic baits or sprays against them, beside trapping and shooting.