White-headed Woodpecker
Encyclopedia
The White-headed Woodpecker (Picoides albolarvatus) is a non-migratory woodpecker
Woodpecker
Woodpeckers are near passerine birds of the order Piciformes. They are one subfamily in the family Picidae, which also includes the piculets and wrynecks. They are found worldwide and include about 180 species....

 that resides in pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...

 forests of the mountain
Mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...

s of western North America. It has a black body (approximately 20 cm long) and white head. It has white primary feathers that form a crescent in flight. Males have a red spot at the nape of the neck.

The range of the White-headed Woodpecker stretches in the mountains from British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 through southern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. They form nests in dead trees or snag
Snag
In forest ecology, a snag refers to a standing, partly or completely dead tree, often missing a top or most of the smaller branches. In freshwater ecology it refers to trees, branches, and other pieces of naturally occurring wood found sunken in rivers and streams; it is also known as coarse woody...

s and reproduce once per year.

Most of the range is occupied by the nominate subspecies. P. a. gravirostris, which has a longer bill - especially in males - and tail, is only found on mountaintops of the southernmost part of the species' range, from the San Gabriel Mountains
San Gabriel Mountains
The San Gabriel Mountains Range is located in northern Los Angeles County and western San Bernardino County, California, United States. The mountain range lies between the Los Angeles Basin and the Mojave Desert, with Interstate 5 to the west and Interstate 15 to the east...

 to San Diego County. Mount Pinos
Mount Pinos
Mount Pinos is a mountain located in the Los Padres National Forest on the boundary between Ventura and Kern counties in California. The summit is the highest point in Ventura County.- Geography :...

 birds are somewhat intermediate. mtDNA cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...

 and ATP synthase
ATP synthase
right|thumb|300px|Molecular model of ATP synthase by X-ray diffraction methodATP synthase is an important enzyme that provides energy for the cell to use through the synthesis of adenosine triphosphate . ATP is the most commonly used "energy currency" of cells from most organisms...

 subunit
Protein subunit
In structural biology, a protein subunit or subunit protein is a single protein molecule that assembles with other protein molecules to form a protein complex: a multimeric or oligomeric protein. Many naturally occurring proteins and enzymes are multimeric...

 6 sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...

 data confirms this arrangement and also suggests that the Mount Pinos birds are closer to P. a. gravirostris (Alexander & Burns, 2006). Apparently, the larger bill of the southern subspecies is an adaptation
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....

 for being better able to feed on the large, spiny cones of Coulter Pine
Coulter Pine
The Coulter Pine or Big-cone Pine is a native of the coastal mountains of southern California and northern Baja California . Isolated groves are found as far north as the San Francisco Bay Area in Mt. Diablo State Park and Black Diamond Mines Regional Preserve...

s (Pinus coulteri).

External links and references

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