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Xanthocephalus xanthocephalus (Bonaparte, 1826)
Yellow-Headed Blackbird
Family: Icteridae

Species account author: Jamie Fenneman
Introduction to the Birds

Photograph

© Ryan Merrill     (Photo ID #9525)

Map


Distribution of Xanthocephalus xanthocephalus in British Columbia.
(Click on the map to view a larger version.)
Source: Distribution map provided by Jamie Fenneman for E-Fauna BC

Species Information

Adult male
The body, including the tail and most of the wings, is glossy black (except for the feathers around the vent, which are yellow-orange); the outer greater primary coverts are white on the upperwing, forming a a narrow patch on the wing when perched but showing as a bold white wing patch when in flight. The head and breast are bright yellow, contrasting sharply with the otherwise black body; the lores are black. The iris is dark, the stout and sharply pointed bill is blackish, and the legs and feet are black.

Adult female
The body, including the wings and tail, is dark brown with a small patch of yellow-orange feathers around the vent. The supercilium, malar area, sides of the neck, and upper breast are dull yellow and the throat is yellowish-white, contrasting with the dark brown crown, nape, and hiondneck and yellowish-brown ear coverts; the lores are darker blackish-brown. The yellow breast patch usually continues onto the lower breast and upper belly as irregular yellowish or whitish streaking or mottling. Bare part colouration is similar to that of the adult male.

Immature male
This plumage is acquired in mid- to late July and is held throughout the first winter and into the following spring. This plumage is similar to the adult female, but has more extensive and brighter yellow on the head and breast, darker and blacker lores, and white edges on the outer primary coverts. Males, including immature males, are also noticeable larger than females.

Juvenile
This plumage is held very briefly (for only several weeks) during the first summer. It differs significantly from any of the subsequent plumages of either sex. The upperparts are dark brownish with broad and extensive pinkish-buff feather edges (upperparts often appearing almost entirely pinkish-buff). The wings are blackish with narrow pinkish-buff edges, especially on the tertials and coverts; the greater and median secondary coverts are broadly tipped with buff or buffy-white, forming two bold pale wing bars. The relatively short, squared tail is dark blackish-brown. The underparts are uniformly pinkish-buff, paler on the lower belly and undertail coverts. The head is also largely pinkish-buff, usually with browner ear coverts and darker blackish-brown lores. The iris is dark, the bill is horn-coloured (usually with a darker tip and culmen), and the legs and feet are pale pinkish.

Measurements
Total Length: 23-24 cm (m>f)
Mass: 44-98 g (m>f)

Source: Twedt and Crawford (1995); Sibley (2000)


Biology

Identification

Identification of all plumages, especially adult males, is straightforward and should prevent few or no problems under normal field conditions.
Vocalizations

The male’s typical song is a very distinctive, unmusical, and unusual series of several hard, clacking notes followed by a prolonged wavering, harsh, raucous buzz or trill: kuk…koh-koh-koh……whaaaAAAAAAAAAAaaa; this entire song last ~4 seconds. Also produces a shorter (~2 seconds) song that usually includes only several fluid or croaking notes, with or without a variable trill: kuuk-ku, WHAAA-kaaaa. Females sometimes produce a harsh, nasal, raspy chatter (cheee-cheee-cheee or tadd-tadd-tadd-tadd) that appears to function as a type of song. Call notes include a loud, rich, liquid tcheck or chack and a quieter, softer clerrk or chuck (primarily given during fall migration).

Source: Twedt and Crawford (1995); Sibley (2000); Jaramillo (2006)

Bird calls (and videos) from Cornell's Lab of Ornithology
Breeding Ecology

Courtship
The Yellow-headed Blackbird has a polygynous mating system, and each male pairs with multiple females. Pair formation occurs on the breeding territories. Sexual chasing, in which one or more males pursue the female at high speeds using deep, rapid wingbeats, is an important component of the courtship process. During these events, the male typically overtakes the female in mid-air and attempts to grasp her rump feathers with his bill; the hold is released once the successful pair have tumbled into the vegetation. Both sexes also perform both perched and (in males) flight displays that variously combine ruffled or sleeked feathers, head movements or postures, exaggerated wingbeats (in flight displays), and a variety of calls or songs.

Nest
Typically nests in colonies, often numbering dozens or even hundreds of pairs. Nest site selection is done solely by the female and occurs shortly after arrival on the breeding grounds and subsequent pair formation (usually in April). The female alone builds the nest over a period of 2-4 (10) days. The bulky, deep, cup-shaped nest is attached to either live or dead emergent vegetation (cattails, tules, etc.) and is situated less than 3 m (usually between 30-60 cm) above the surface of the water. It is 13-14 cm wide and 13-15 cm deep, with a compact inner cup 6.5-7.5 cm across and ~6.5 cm deep. The nest is usually supported by 4-5 stems of emergent vegetation, some of which may be as much as 15 cm apart. Very rarely, emergent shrubs such as willows may provide support for the nest. The nest itself is composed almost entirely of dead vegetation, usually dominated by the same emergent species as is supporting the nest as well as additional material such as grasses, sedges, mosses, leaves, and feathers. Some nests are lined with finer materials such as fine grasses or (in cattail marshes) cattail down. The nest occasionally includes a partial canopy of woven grasses and stems.

Eggs
A single clutch of 3-4 (6) eggs is laid between mid-May and early (rarely mid-) June and is incubated by the female for 10-13 days before hatching. The smooth, glossy eggs are greyish-white to pale greenish-white with extensive and evenly-distributed brown, rufous, and grey blotches and speckles. There are no records of second clutches in British Columbia, although replacement clutches (if the first clutch is lost) will be laid as late as July. Eggs occur in B.C. between mid-May and late July. This species is rarely affected by Brown-headed Cowbird parasitism.

Young
The young remain in the nest for (7) 9-12 (14) days following hatching, with nestlings present in B.C. between late May and late July. Nestlings are altricial and downy, with sparse buff down on the head and back. Both parents tend to the young, although the female may contribute a greater share (and are the sole parental attendant during the first four days after hatching). After fledging, the young are tended by the parents for several days before dispersing and becoming independent. Fledglings are initially incapable of flight, and clamber through the emergent vegetation while being fed by the parents; most fledglings are capable of flight by ~20 days of age. Juveniles join adults to form large molting aggregations in late summer prior to fall migration.

Source: Twedt and Crawford (1995); Baicich and Harrison (1997); Campbell et al. (2001)
Foraging Ecology

Aquatic invertebrates, particularly insects and insect larvae, dominate the diet throughout the breeding season, while weed seeds and grains (wheat, oats, barley, millet, etc.) become increasingly important through the late summer, fall, and winter. When the abundance of aquatic invertebrates at a colony is low, individuals regularly wander into adjacent upland habitats (e.g., cultivated fields) in search of terrestrial invertebrates. When foraging on aquatic invertebrates, most prey are captured at or near the water’s surface or along the muddy or sandy margins of wetlands. Typically forages in flocks outside of the breeding season, either in single-species flocks containing only Yellow-headed Blackbirds (such as during fall migration) or as singles associated with large flocks of other blackbird species (primarily during the winter).

Source: Twedt and Crawford (1995)

Habitat


During the breeding season, this species is closely tied to freshwater marshes, slough, ponds, and lakeshores with an abundance of tall emergent vegetation (especially cattails and tules), although foraging birds regularly venture into nearby upland habitats such as agricultural areas, fields, grasslands, sewage lagoons, and feedlots. It rarely breeds in freshwater wetlands with little or no emergent vegetation or those that are dominated by emergent shrubs such as willow. Migrants occur both in freahwater and upland habitats, and are often associated with agricultural habitats in the company of other species of blackbirds (Brewer’s Blackbird, Red-winged Blackbird, Brown-headed Cowbird). Vagrants occasionally occur in coastal estuaries, beaches, or suburban parks.

Source: Campbell et al. (2001)

Distribution

Global Range

Breeds from British Columbia east to southern Manitoba, with local populations farther east to southern Ontario, south through the western and central United States to southern California (and extreme northern Baja California), central Arizona, central New Mexico, and northern Texas. It winters primarily from the southwestern United States (southern Arizona, southern New Mexico, southern and western Texas) south through northern and central Mexico, with some birds wintering in southern California.
BC Distribution

Breeding
Highly local throughout its breeding range, even in areas where it is relatively common. Fairly common at low elevations throughout the south-central interior north to the Cariboo-Chilcotin region (Williams Lake, Riske Creek, etc.), becoming uncommon and sporadic farther north through the central interior to the Vanderhoof region. Also uncommon to locally fairly common in southern regions of the coutheastern interior such as the Kettle River watershed, Grand Forks area, lower Columbia River valley, and (especially) the Creston Valley; also locally fairly common along the southern Rocky Mountain Trench north to Windermere Lake, becoming uncommon farther north to Golden; may occasionally breed near Valemount at the north end of Kinbasket Lake. Uncommon in the Peace River lowlands of northeastern B.C.

A single isolated breeding population occurs in the Lower Mainland (Iona Island) and represents one of few established colonies of the species from the coast of the Pacific Northwest. Occasional isolated pairs have also bred elsewhere in the Lower Mainland (east to Chilliwack), but the Iona Island population is the only location with a perennial breeding population.

Winter
Very rare in the Lower Mainland and on extreme southern Vancouver Island (Victoria area) during the winter, as well as through the southern Okanagan (north to Kelowna) and Creston Valleys of the southern interior. Casual farther north in the south-central interior to the Thompson River valley. Accidental in the central interior in winter (Prince George area).

Migration and Vagrancy
Fairly common spring and fairly common to locally common fall migrant through the south-central interior and locally in the south-eastern interior (Creston Valley), and uncommon during spring and fall migration in other areas of its breeding range in the province (central interior, Peace River area, elsewhere in the southeastern interior). Very rare to rare spring and fall migrant elsewhere throughout the southern and central regions of the province, including Vancouver Island, and the southern mainland coast.

This species is an early spring migrant, with earliest birds arriving in southern interior in late March. Numbers of spring migrants build through April to reach a peak northward movement in late April and early May. Farther north in the central interior and Peace River lowlands the first spring migrants to not arrive until late April, with the bulk of the breeding population arriving through May. Spring migration is slightly later on the south coast than in the southern interior, with most birds occurring from mid-April through May (some birds arriving as early as early April). Most vagrants elsewhere on the south coast (Vancouver Island, etc.) occur between mid- to late April and mid-June.

Fall migration occurs primarily between late July and mid-September, with most birds departing the province through August; occasional individuals linger in the southern interior and on the south coast into October and very rarely into November. Vagrants on the south coast outside of the Lower Mainland occur primarily between September and November (occasionally as early as July or as late as December).

Source: Campbell et al. (2001)

Conservation

Population and Conservation Status

The Yellow-headed Blackbird is particularly susceptible to droughts, and colonies often disappear following the loss of wetland habitat due to these factors. Fortunately, however, this species is adapted to periodically move its colonies in response to changing environmental conditions (especially water levels) and as such is able to withstand relatively severe drought events provided that at least some suitable wetland breeding habitat remains in the region. Once conditions improve, individuals and groups then recolonize the original sites. As a result, populations in a given colony or regional population often fluctuate widely from year to year.

Populations in British Columbia appear to have increased and expanded over the past century, particularly in the central interior (where numbers have increased since the 1940s), in the southern Rocky Mountain Trench (where it was historically known only from the Cranbrook area), and the Peace River area of northeastern B.C. (where it was unknown prior to the 1970s). On the coast, the first evidence of breeding in the Lower Mainland occurred in the 1960s, with the abundance at the single main colony (Sea Island) peaking in the 1970s. The Sea Island colony has subsequently moved a short distance to nearby Iona Island following destruction of the breeding habitat on Sea Island for the expansion of the Vancouver International Airport. It currently appears to be stable at a reduced level.

Despite annual fluctuations and its susceptibility to drought, the Yellow-headed Blackbird is currently relatively common in British Columbia, with stable or even increasing local populations. It is not recognized as a species of concern by either provincial (B.C. CDC [Conservation Data Centre]) or federal (COSEWIC [Committee on the Status of Endangered Wildlife in Canada]).

Source: Campbell et al. (2001)

Taxonomy


The Yellow-headed Blackbird is monotypic, with no recognized subspecies, although populations breeding in northwestern portions of the species’ range (such as in B.C.) average slightly larger than birds from elsewhere.

Source: Twedt and Crawford (1995)

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)		COSEWIC
NativeS4BYellowNot Listed



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