Acorn Woodpecker
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{{Taxobox | color = pink | name = Acorn Woodpecker | image = AcornWoodpecker23.jpg | regnum = Animalia | phylum = Chordata | classis = Aves | ordo = Piciformes | familia = Picidae | genus = Melanerpes | species = M. formicivorus | binomial = Melanerpes formicivorus | binomial_authority = (Swainson, 1827) }}
The Acorn Woodpecker (Melanerpes formicivorus) is a medium-sized woodpecker, 21 cm long with an average weight of 85 g.
The adult has a black head, back, wings and tail, white forehead, throat, belly and rump. The eyes are white. The adult male has a red cap starting at the forehead, whereas females have a black area between the forehead and the cap.
The breeding habitat is forested areas with oaks in the hills of coastal California and the southwestern United States south to Colombia, and this species occurs from about 1000 m altitude to the timberline. The breding pair excavate a nest in a large cavity in a dead tree or a dead part of a tree. A group of adults may participate in nesting activities: field studies have shown that breeding groups range from monogamous pairs to breeding collectives of seven males and three females, plus up to 10 nonbreeding helpers.
Acorn Woodpeckers are larder hoarders. Breeding groups gather acorns and create a granary by drilling holes in a dead tree and stuffing acorns into them. The acorns are visible, and the group defends the tree against potential cache robbers. The acorns represent a significant part of their diet; they also eat insects, picking them off tree bark or catching them in flight, and in addition fruit, seeds and sometimes tree sap.
This bird is a permanent resident throughout its range. They may relocate to another area if acorns are not readily available.
References
- Haydock J., Koenig W. D., & Stanback, M. T. (2001). Shared parentage and incest avoidance in the cooperatively breeding acorn woodpecker. Molecular Ecology, 10, 1515-1525.
- Stiles and Skutch, A guide to the birds of Costa Rica ISBN 0-0814-9600-4
External links
- Acorn Woodpecker, a bibliographic resource
- USGSda:Agernspætte