Yellow-headed Blackbird

The Yellow-headed Blackbird is a striking bird of marshes, open fields and pastures. It’s distinct appearance along with its distinct call, which sounds like rusty hinges, make this bird easy to identify in the field. It breeds from central BC, northern Alberta, central Saskatchewan, southern Manitoba and Wisconsin, Illinois, across the prairies west to southern California, northern New Mexico. It winters in southern California, Arizona, New Mexico and Mexico.

Adult Male (spring/summer)

Yellow head, neck and breast. Body plumage, lore, eye-stripe are all black except for prominent white wing –patches which are slightly visible when the bird is perched, but very conspicuous in flight. The legs and eyes are black. Males are significantly larger than females.

Adult Female (spring/summer)

Grayish brown body with pale yellow primarily on breast and throat, but also on neck and supraloral stripe. White streaking merges with yellow on breast and brown abdomen. No prominent white-wing patches.

Juvenile

Dark brown with buffy edgings on back and wing; head and breast are mostly tawny.

General:

This is a large bodied passerine with yellow head and breast. Length: 20-28cm. Wingspan: 36-43cm. Weight: 65g.

Behaviour:

Forages by walking on the ground, sometime hopping, in open fields or near the water’s edge; also forages low in marsh vegetation. This blackbird may follow farm machinery in fields to feed on insects turned up by the plow. It will climb up or slide down vegetation to attain a suitable, stable perch.

The Yellow-headed Blackbird is a diurnal migrant, migrating in small flocks that tend to be long, loose and irregular. It congregates at staging areas and gathers in mixed species flocks of blackbirds to roost at night in emergent vegetation wetlands. It is also found in large mixed flocks during the winter. Its flight is slightly undulating.
During the breeding season the yellow-headed blackbird feeds mostly on aquatic insects. Post breeding consumption consists mainly of cultivated grains and weed seeds.

Habitat:

Primarily prairie wetlands. It is also common in wetlands associated with quaking aspen parkland, mountain meadows and arid regions. Scattered colonies occur in forest edges and on larger lakes in mixed-wood boreal forest.

Information:

The Yellow-headed Blackbird nests in emergent vegetation of wetlands and forages within those wetlands and surrounding grasslands, croplands or savanna. The nest is constructed over deeper water, primarily in cattails, bulrushes or reeds, often in the same wetlands as nesting Red-winged Blackbirds that are relegated to emergent vegetation over shallow water. The nest is a deep basket of water-soaked dead grasses, reeds, cattails, woven and wound around reed stems forming a tight nest when dried a few inches to several feet above water. Three to five pale gray to pale green eggs evenly splotched or speckled with browns and grays are laid.

Similar species:

Red-winged Blackbird, Boat-tailed Grackle, Great-tailed Grackle, Bobolink.

Conservation Status:

Continental populations appear to be in no jeopardy provided wetland habitat remains intact. Listed as Least Concern.

Capture Rates:

The Yellow-headed Blackbird is a vagrant visitor to Colony Farm preferring Prairie wetlands and emergent wetlands throughout non-forested regions of the west. Capture rates of this species are therefore low at the banding station reflecting one individual caught in May of 2012.

Molt Summary:

PF: HY partial (Jul-Sep): PB: AHY complete (Jun-Aug); PA absent-limited? (Jan-Apr).
Molts occur on the summer grounds.
Preformative molt usually includes all med and gr covs, but no terts or rects.
Adult PB: appears to commence earlier in SYs than in ASYs.
PA: more study needed.

This SY female in May is showing the yellow of the head and breast mottled brown diagnostic of first year females.

In Yellow-headed Blackbird the preformative molt is partial meaning only body feathers and some wing coverts and possibly tertials and central retrices are replaced.

This preformative molt normally includes all median and greater coverts but no tertials or retrices and little is know about the prealternate molt which is suspected to be absent or limited.

This bird has replaced only the 5 inner GCs and retained the outer 5 GCs, a clear molt limit and ‘step-in’ between replaced and retained feathers (red arrow).

In addition to the yellow of the head and breast being mottled with brown in SY females the outer primary coverts are relatively tapered and often have white tipping as can be seen in the photo below (green arrow).