|Species: Black-headed Grosbeak
In many areas of
western North America, the melodious song of the Black-headed
Grosbeak is a familiar harbinger of spring. Adult males have a
flashy black, white, and cinnamon plumage; females are relatively
drab buff and brown. Despite their showyplumage, males share about
equally with females in incubating and feeding young.
One interesting feature of the Black-headed Grosbeak is that males
do not attain definitive nuptial plumage until their second breeding
season and vary in appearance from female-like to adult-male-like in
their first potential breeding season. Only yearling males that most
closely resemble adult males are able to defend a territory and
attempt to breed.
This species breeds from subalpine forests to desert riparian zones
throughout western North America from southwestern Canada to
Medium sized cardinal finch. Stocky with a large head and very large
Length 17-20 cm. Weight 45g.
Black head, large pale bill, rusty orange collar, breast, sides and
rump; yellow belly and wing linings. Bold white wing bars on black
wing. In flight, shows white patches on wings and yellow “armpits”.
Brown head with buffy to white crown and eye-stripe, a pale chin,
brown wings and tail with indistinct buffy spots, and heavily
streaked body plumage that is dull cinnamon to buff with variable
amounts of yellow. Yellow “armpits”.
Generally resemble adult females, but males are brighter on average
Adult males are distinct from all other species. Females and
especially juveniles are sometimes confused with Rose-breasted
Grosbeaks, but females of that species are more coarsely streaked,
and their breast, eye-stripe, and crown stripes tend toward white,
generally lacking the buffy to yellow cast characteristic of female
Black-headed Grosbeaks. Difference in colour of wing lining-lemon
yellow in female Black-headed Grosbeak and saffron yellow in female
Rose-breasted Grosbeak-is diagnostic.
Flight is slightly undulation with rapid wing beats except for
flight displays given in spring.
Song is delivered from a high perch and occasionally in flight.
Forages in the foliage of trees, eating pine and other seeds, wild
berries, insects and spiders. Comes to bird feeders for sunflower
seed, other types of seed, and fruit.
Common in open woodlands, forest edges, woods along rivers, edges of
second-growth mixed forests, mountain forest edges: orchards and
Relatively tolerant of human disturbance, it breeds in yards and
gardens if adequate cover for nesting and feeding is available.
Grosbeak hybridizes with its eastern counterpart, the Rose-breasted
Grosbeak, along their mutual boundary. This situation arose when the
treeless prairies, which once formed a barrier between the two
species, became dotted with towns and homesteads, providing suitable
habitats for both species. The Black-headed Grosbeak is a rather
still and secretive bird throughout the summer.
The nest is made of twigs, rootlets, flower heads, and stems lined
with stems and rootlets, placed in the fork of a tree or shrub
4-25ft above the ground. 2-5 blue-white or green-white with brown
Population is large
and relatively stable. On breeding rounds Black-headed Grosbeaks
benefit from some human activity. Irrigation of arid regions,
planting of orchards, creation of openings in dense forest improve
habitat for grosbeaks. However, much habitat has been lost to
urbanization. It is difficult to assess the net affect of human
activities on breeding grounds on population.
Black-headed Grosbeaks utilize diverse habitats and are
plentiful during the breeding season at Colony Farms. Males
arrive shortly before females in late spring and numbers
increase, peaking in August corresponding to juvenile
dispersal as is reflected by the capture rates (2010-2012;
standardized as birds captured per 100 net hours) from May -
September. Grosbeaks are medium distance migrants, moving
southward to central Mexico for the winter as seen by our
zero capture rate between October - April.