Acorn Woodpecker

Melanerpes formicivorus

Order PICIFORMES - Family PICIDAE

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1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

The clown-faced Acorn Woodpecker is a common bird of western oak forests. It lives in extended family groups, and all members of the group spend hours and hours storing thousands of acorns in carefully tended holes in trees and telephone poles.

Cool Facts

• The Acorn Woodpecker has a very complicated social system. Family groups hold territories, and young woodpeckers stay with their parents for several years and help the parents raise more young. Several different individuals of each sex may breed within one family, with up to seven breeding males and three breeding females in one group.

• All members of an Acorn Woodpecker group spend large amounts of time storing acorns. Acorns typically are stored in holes drilled into a single tree, called a granary tree. One granary tree may have up to 50,000 holes in it, each of which is filled with an acorn in autumn.

• The Acorn Woodpecker will use human-made structures to store acorns, drilling holes in fence posts, utility poles, buildings, and even automobile radiators. Occasionally the woodpecker will put acorns into places where it cannot get them out. Woodpeckers put 220 kg (485 lb) of acorns into a wooden water tank in Arizona. In parts of its range the Acorn Woodpecker does not construct a granary tree, but instead stores acorns in natural holes and cracks in bark. If the stores are eaten, the woodpecker will move to another area, even going from Arizona to Mexico to spend the winter.

• In groups with more than one breeding female, the females put their eggs into a single nest cavity. A female usually destroys any eggs in the nest before she starts to lay, and more than one third of all eggs laid in joint nests are destroyed. Once all the females start to lay, they stop removing eggs.

Description

• Size: 19-23 cm (7-9 in)
• Wingspan: 35-43 cm (14-17 in)
• Weight: 65-90 g (2.29-3.18 ounces)

• Medium-sized Woodpecker.
• Back and chest black.
• Head black, white, and red.

• Black in face surrounds white eye.
• Front of face white or cream yellow.
• Black around base of bill.
• Top of head red.
• Bill black.
• Belly white.
• Rump white.
• Black streaks extending from chest into belly.
• White patch in wings obvious in flight.

Sex Differences

Sexes similar, but male has solid red crown; female has black band between forehead and red.

Male

Red from nape to white forehead.

Female

Rear of crown red. Forehead white, separated from red by black area.

Immature

Juvenile similar to adult male, but with dark eye.

Similar Species

• No other woodpecker has black back, white belly, and black-white-and-red face pattern.
• White-headed Woodpecker has all-black body and an all-white face.

Sound

Most common call a loud "waka-waka-waka."

»listen to songs of this species

Range

Summer Range

Resident in western Oregon, California, Arizona, New Mexico and western Texas, southward through Mexico and Central America. Also isolated populations in Colombia.

Habitat

Oak and pine-oak woodlands, generally in mountains. Common in urban parks and suburban areas where oaks are common.

Food

Insects, acorns, sap, and fruits.

Behavior

Foraging

Captures insects by flycatching high above tree canopy or by gleaning off tree limbs. Huge numbers of acorns stored in holes in trees.

Reproduction

Nest Type

Nest in cavity in tree or tree limb. No structure, but wood chips in bottom of cavity.

Egg Description

White.

Clutch Size

Usually 4 eggs. Range: 2-8.

Condition at Hatching

Naked and helpless.

Conservation Status

Common. Populations stable.

Other Names

Pic glandivore (French)
Carpintero de bellota (Spanish)

Sources used to construct this page:

Koenig, W. D., P. B. Stacey, M. T. Stanback, and R. L. Mumme. 1995. Acorn Woodpecker (Melanerpes formicivorus). In The Birds of North America, No. 194 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.