Threetoed woodpecker

Picoides tridactylus

SUBFAMILY Picinae

TAXONOMY

Picus tridactylus Linnaeus, 1758, Sweden. Although North American and Eurasian populations appear similar, recent studies suggest significant genetic differences. Three races are recognized in the New World, five in Eurasia.

OTHER COMMON NAMES

English: Northern three-toed woodpecker; French: Pic tri-dactyl; German: Dreizehenspecht; Spanish: Pico Tridáctilo.

PHYSICAL CHARACTERISTICS

8-9.5 in (20-24 cm); 1.6-2.7 oz (46-76 g) a medium-sized woodpecker with black above, white below, varying extent of barring on flanks and white on back; male has a yellow forehead and crown, female has a whitish crown with fine black streaks; immature has duller plumage that is somewhat brown; only three toes on each foot.

DISTRIBUTION

Resident from near the tree line in northern Alaska, northern Canada, northern Eurasia, south to northern tier of United States, mountains of southern Europe, western China, northern Mongolia, northern Korea, and Japan. Wanders south in winter to New England, north central United States. P. t. tridactylus, northern Eurasia, Scandinavia, Latvia, to Mongolia, southeastern Siberia, and Sakhalin Island; P. t. crissoleucus, northern taiga from Urals to Sea of Okhotsk; P. t. albidor, Kamchatka; P. t. alpinus, mountains of central, southern, and southeastern Europe, northeastern Korea, Hokkaido, Japan; P. t. funebris, southwestern China to Tibet; P. t. dorsalis, Rocky Mountains, Montana to Arizona and New Mexico; P. t. fascia-tus, western North America, Alaska, and Yukon south to Oregon; P. t. bacatus, eastern North America, Alberta east to Labrador and Newfoundland, south to Minnesota and New York.

HABITAT

Coniferous forest; less often mixed coniferous-deciduous forest.

BEHAVIOR

Nonmigratory, often very quiet; very arboreal; populations respond to forest insect outbreaks.

FEEDING ECOLOGY AND DIET

Feeds primarily on wood-boring insects, their larvae and pupae; forages lower in winter than at other times; when sexes forage together, females forage higher than males.

REPRODUCTIVE BIOLOGY

Monogamous; breeding activities generally extend from mid-March through June; nest cavities usually excavated in dead stub; pair share excavation, incubation, and care of young; clutch size 3-6 eggs; incubation period 11-14 days; young fledge at 22-26 days.

CONSERVATION STATUS

Fairly common, not threatened.

SIGNIFICANCE TO HUMANS None known. ♦

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