[order] Passeriformes | [family] Parulidae | [latin] Dendroica virens | [UK] Black-throated Green Warbler | [FR] Paruline à gorge noire | [DE] Grünwaldsänger | [ES] Chipe de Garganta Negra | [IT] Dendroica verdastra golanera | [NL] Gele Zwartkeelzanger

Gele Zwartkeelzanger determination

copyright: Robert Schaefer

Black-throated green warblers range in size from 11.5 to 14 centimeters in length. A breeding adult male has a black chin, throat, and upper chest with a bright yellow face. The underside is mostly white with black lines running down the sides. A pale yellow color stretches across the lower chest and chin area. The wings are mostly gray with white streaks. Mature females are similar to males except not as bright and with less black on their chins. There is not much change in appearance during migration. A young female may have little or no black on its chin. Immature males and females have a yellowish belly rather than a white one.

Preferred breeding habitat of black-throated green warblers varies from the coastal plains to mountain ranges, but is mainly the coniferous and mixed forest regions of the northern United States and the Appalachian mountain range. In their winter range they also prefer woody habitats such as deciduous or coniferous forest edges.

Black-throated green warblers are found through much of the Nearctic Region. In the summer they range from eastern British Columbia throughout southern Canada as far north as Alberta and as far east as Newfoundland. Their summer range includes much of the Appalachian mountains, as far south as South Carolina, Georgia, Alabama, and the Ozarks of northwest Arkansas. They are also found in the Great Lakes region and into Indiana and Illinois during the summer. An isolated subspecies, D. virens waynei, breeds in the cypress swamps of Virginia, North Carolina, and South Carolina.

Black-throated green warblers eat mostly insects, primarily caterpillars, such as spruce budworms. They have also been known to eat poison ivy berries during migration and the pollen of Cecropia trees in their winter range. During the breeding season, black-throated green warblers eat exclusively insects.

This species has a large range, with an estimated global Extent of Occurrence of 3,300,000 km². It has a large global population estimated to be 9,600,000 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]

Males reach the breeding ground first, with females following shortly after. This species is seasonally monogamous with males rarely taking a second mate. Mating begins with a male display to the female that includes fluffing, in which the male fluffs out his feathers. After mates are chosen, the male usually remains near the female to aid in nest building. After the young leave the nest, the male and female go their separate ways. Males are protective of the nesting area during mating season.
All mating takes place in the spring. This occurs in mid April in the Appalachian mountains, early May in the northern United States, and as late as mid-May in Canada. One brood is produced per year with clutch sizes of 3 to 5 eggs. After 12 days of incubation, it takes about 8 to 10 days for the birds to leave the nest.
A breeding female will spend 80% of her time with her eggs. Only the female broods while the male spends his time defending the nest. Time allotted to brooding decreases rapidly over the course of a few days. No brooding occurs within the last few days of the fledgling’s time in the nest. The female does all the feeding, although the male may contribute by bringing some food to the nest. The male may try to feed the young but this is very rare. The parents carry the food (mostly invertebrates such as spiders and insects) in their bill and place it in the beaks of their young.

A North American species, breeding from south-central British Columbia east to southern Labrador and Newfoundland, south to Minnesota, eastern Tennessee, northern Georgia, and South Carolina; winters from southern Texas and southern Florida south through Central America to Colombia, and in West Indies south to Guadeloupe and Dominica. Recorded in Germany and Iceland (immature ) found dead on ship, 19 September 1984.