American three-toed woodpecker
|American three-toed woodpecker range. A small portion of the Eurasian three-toed woodpecker P. tridactylus range is visible too.[n 1]|
|Eurasian and American three-toed woodpeckers ranges.[n 1]|
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 breeding habitat is coniferous forests across western Canada, Alaska and the western United States. It has also been breeding in various spots in Michigan's upper peninsula, and has been recorded breeding in Minnesota five times.
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.
- BirdLife International and NatureServe (2014) Bird Species Distribution Maps of the World. 2014. Picoides tridactylus. In: IUCN 2014. The IUCN Red List of Threatened Species. Version 2014.3. "Archived copy". Archived from the original on 2014-06-27. Retrieved 2014-06-27.. Downloaded on 26 May 2015.
- 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.; Rohwer, Sievert; Andreev, Alexander V.; Dittman, Donna (July 1995). "Trans-Beringia Comparisons of Mitochondrial DNA Differentiation in Birds" (PDF). Condor. Cooper Ornithological Society. 97 (3): 639–649. doi:10.2307/1369173. JSTOR 1369173.