[order] Passeriformes | [family] Fringillidae | [latin] Hesperiphona vespertina | [UK] Evening Grosbeak | [FR] Gros-bec errant | [DE] Abendkernbeisser | [ES] Pepitero Vespertino | [IT] Frosone vespertino americano | [NL] Avonddikbek

Avonddikbek determination

copyright: Ann Hoover

Close in size to Hawfinch but with proportionately rather smaller bill and head. Large, heavy, strong-billed, and short-tailed finch, with form somewhat recalling Hawfinch but in west Palearctic unique colours of pale bill, dusky and pale yellow head and body, and white-patched black wings and tail. Male has distinctive yellow forecrown, with white on flight-feathers restricted to bold patch on inner greater coverts, inner secondaries and tertials; Female lacks yellow on head and has greenish body with additional white panel over bases of primaries and bold white tips on central tail-feathers. Unmistakable. In west Palearctic, only Hawfinch bears passing resemblance in shape, but differs distinctly in brown-buff body plumage and wholly dark tertials, with white panel on wing brightest towards carpal joint. Flight rather heavy, but swift and strong, with bursts of wing-beats producing bounding undulations; flies high above trees when moving between feeding areas.

Breeds in boreal Nearctic coniferous forest, usually tall and mature, but also in mixed forest, including second growth, and at times in willows growing beside rivers, or in town gardens and shade trees. In winter, strongly attracted to bird-tables with sunflower seeds. Accessible salt is also an attraction. Recent changes have involved major eastward extension of range and more frequent wintering in and around human settlements, including parks and gardens.

Breeds in North America, from south-west and north-central British Columbia east to Nova Scotia, south through Rocky Mountains to southern Mexico, and east of the mountains south to central Minnesota, southern Ontario, northern New York, and Massachusetts.

These birds forage in trees and bushes, sometimes on the ground. They mainly eat seeds, berries and insects. Outside of the nesting season, they often feed in flocks. Sometimes, they will swallow fine gravel.

This species has a large range, with an estimated global Extent of Occurrence of 3,900,000 kmē. It has a large global population estimated to be 6,000,000 individuals (Rich et al. 2003). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

Evening Grosbeaks are generally monogamous, although when there is an unusually plentiful food supply, polygamy can occur. In most cases, pairs form before the birds arrive on the breeding grounds. Nests are typically located high up in trees, on horizontal branches well out from the trunk or in vertical forks. The female builds the nest, which is a loose saucer of roots and twigs lined with fine grass, moss, rootlets, needles, and lichen. After laying 3-4 eggs, she incubates them for 12 to 14 days. The male brings food to the female on the nest. Both members of the pair feed the young. Young Evening Grosbeaks leave the nest after 13 to 14 days, but remain near the nest for 2 to 5 days, and the adults continue to feed them for some time after that. Some pairs raise two clutches in a single season.

Erratic, nomadic, or inconsistently migratory. May arrive and depart regularly for several years, then not appear at all for a year or more. During range expansion to eastern North America, 1920-50, distribution and movements correlated well with widespread planting of box elder Acer negundo, on whose fruits it feeds in winter. Since 1950, summer occurrence correlates well with epidemics of spruce budworm, on whose larvae it feeds. It is an extremely rare vagrant to the British Isles, with just two records so far.