American three-toed woodpecker
This woodpecker has a length of 21 cm (8.3 in), a wingspan of 38 cm (15 in), and an average weight of 55 g (1.9 oz); its maximum lifespan in the wild is 6 years. It closely resembles the Black-backed Woodpecker, which is also three-toed. Until recently, it was considered to be the same species as the Eurasian Three-toed Woodpecker, (P. tridactylus). Adults are black on the head, wings and rump, and white from the throat to the belly; the flanks are white with black bars. The back is white with black bars and the tail is black with the white outer feathers barred with black. The adult male has a yellow cap.
The female lays 3 to 7 but most often 4 eggs in a nest cavity in a dead conifer or sometimes a live tree or pole. The pair excavates a new nest each year.
This bird is normally a permanent resident, but northern birds may move south and birds at high elevations may move to lower levels in winter.
These birds often move into areas with large numbers of insect-infested trees, often following a forest fire or flooding. This bird is likely to give way to the Black-backed Woodpecker where the two species compete for habitat.
- P. d. dorsalis, nominate Western race.
- P. d. fasciatus, Rocky Mountain race.
- BirdLife International (2012). "Picoides dorsalis". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Wasser, D. E.; Sherman, P. W. (2010). "Avian longevities and their interpretation under evolutionary theories of senescence". Journal of Zoology 280 (2): 103. doi:10.1111/j.1469-7998.2009.00671.x.
- Zink, Robert M.; Sievert Rohwer, Alexander V. Andreev & Donna Dittman (July 1995). "Trans-Beringia Comparisons of Mitochondrial DNA Differentiation in Birds". Condor (Cooper Ornithological Society) 97 (3): 639–649. doi:10.2307/1369173. JSTOR 1369173.
- Three-toed Woodpecker Information – USGS Patuxent Bird Identification InfoCenter
- American Three-toed Woodpecker photos VIREO
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