Acorn Woodpecker

Acorn Woodpecker

Summary:

Profile Acorn Woodpecker
[Authority] Swainson, 1827 | [group] Woodpeckers | [order] PICIFORMES | [family] Picidae | [latin] Melanerpes formicivorus | [UK] Acorn Woodpecker | [FR] Pic galndivore

[Authority] Swainson, 1827 | [group] Woodpeckers | [order] PICIFORMES | [family] Picidae | [latin] Melanerpes formicivorus | [UK] Acorn Woodpecker | [FR] Pic galndivore | [DE] Eichelspecht | [ES] Carpintero careto (Cr), Carpintero Arlequin (Mex), Cheje Bellotero, Garacaca, Guaracaca (HN) | [NL] Eikelspecht | copyright picture

Note the clownish black, white, and red head pattern. A black-backed woodpecker showing a conspicuous white rump and white wing patches in flight. Both sexes have whitish eyes, red on crown.

Oak woods, groves, mixed forest, oak-pine canyons, foothill Seldom away from oaks. Most common where several species of oaks occur together (t
his insures against total failure of local acorn crop, as different oaks respond to different conditions). May be in open oak groves near coast, pine-oak woods in mountains, streamside sycamores next to oak-covered hillsides.

Omnivorous; eats many acorns and insects.
Acorns about half of annual diet, and are of major importance in winter. Also feeds on insects, particularly ants. Eats various nuts, fruits, seeds, sometimes birds eggs.
b Behavior: Members of group harvest acorns in fall, store
them in hole-studded trees, feed on them in following seasons. Insects are gleaned from surface of tree or caught in flight. Unlike most woodpeckers, rarely or never excavates in wood for insects. May feed on sap, digging pits in bark or visiting those m
ade by sapsuckers.


This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern. [conservation status from birdlife.org]


Breeding group consists of pair, usually assisted by additional birds, generally the pairs earlier offspring or other related individuals. Group may consist of 10+ birds (as many as 16), which defend communal food stores and nesting territory year-round.

b Nest: Site is a cavity in tree (almost always dead tree or dead branch of live tree), 5-60 above ground, usually 12-30. Excavated by both sexes and by helpers. No nest material other than wood chips in cavity.
b Clutch 3-
7. White. Nests with more eggs (up to 17 recorded) must result from more than one female laying. Incubation mainly by both parents at first, with helpers soon joining in; incubating birds take turns, with rapid turnover, sometimes changing places many
times per hour. Incubation period 11-14 days.
b Young: Are fed by both parents and by helpers, and leave nest at about 30-32 days. 1-2 broods per year, possibly sometimes 3.

Resident, western United States to Colombia. b
Migration: Mostly permanent resident throughout range. Stragglers may appear far from nesting areas at any season. If acorn crops fail, may stage small invasions to lowland valleys in fall and winter.

Specification

  1. Measurements
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  6. Breeding
  7. incubation min.: 0 days
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  9. fledging min.: 0 days
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  11. broods 0
  12. eggs min.: 0
  13. eggs max.: 0
  14. Conservation Status
  15. Acorn Woodpecker status Least Concern

Subspecies

  1. Melanerpes formicivorus flavigula
  2. Colombia
  3. Melanerpes formicivorus striatipectus
  4. Nicaragua to w Panama
  5. Melanerpes formicivorus lineatus
  6. Chiapas (s Mexico) to n Nicaragua
  7. Melanerpes formicivorus albeolus
  8. e Chiapas (se Mexico) to Belize and ne Guatemala
  9. Melanerpes formicivorus formicivorus
  10. sw USA to se Mexico
  11. Melanerpes formicivorus angustifrons
  12. s Baja California (Mexico)
  13. Melanerpes formicivorus bairdi
  14. Oregon (USA) to n Baja California (Mexico)
  15. Melanerpes formicivorus
  16. NA, LA nw USA to Colombia
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