National Park Service Klamath Network Featured Creature U.S. Department of the Interior

Natural Resource Stewardship & Science Klamath Network Acorn February 2019 formicivorus Field Notes Behavior and Feeding males mate with 1–3 females, assisted by up Acorn are highly social, which to 10 male and female nonbreeding helpers. is obvious if you happen upon the noisy Multiple males may mate with the same chatter of a social group. The sing-songy female and vice versa, known as “waka-waka-waka” is a common greeting opportunistic polygynandry. Cobreeding call—sometimes also used antagonistically. females lay eggs in the same nest. Competition to pass on one’s own genes Acorn woodpeckers eat a variety of insects, can get tough, though, with each breeding

including flying ants, wasps, and beetles, female regularly removing other eggs from which are snagged in flight from a treetop the joint nest (to be eaten by the group) perch, as flycatchers do. During the winter, until she lays her first egg. An average of when insects are rare, acorn woodpeckers five white eggs are laid per clutch, hatching King NPS/Susie turn to their backup food supply: acorns, in 11 days into nestlings that then fledge in (Melanerpes formicivorus). which actually comprise half their diet and 30–32 days. The nonbreeding adults help General Description are vital to the species’ survival. A poor or incubate, brood, and feed the young. failed acorn crop can force the social group Raucous and colorful, Melanerpes to move in search of food and hamper formicivorus is a medium-sized woodpecker reproduction. In the fall, acorns are with a knack for turning trees into kitchen collected and stored in individually drilled pantries. Topped by a bright red crown, the holes in 1 or 2 “granary” trees that anchor a acorn woodpecker’s distinct “clown-face” social group’s territory. The holes are is black and white, with white eyes. Its drilled into dead limbs or thick bark, glossy black back contrasts with a white avoiding live tree tissue. Each year, the rump and wing patches seen in flight. Its woodpeckers drill a few new holes into white to yellowish throat ends at a black which the nuts are snugly pressed—so collar, which fades to dark streaking and snugly, in fact, that squirrels and other then a white belly. Its flight is undulating. aspiring thieves cannot pry them out. One Fence post granary in woodland. S. Daw storage tree had 50,000 storage holes! Habitat and Distribution Conservation Undeterred by humans, they may also The acorn woodpecker’s reliance on acorns Acorn woodpeckers appear stable, but their transform utility poles, fence posts, or even controls its habitat. Common in pine-oak need for diverse oak woodlands and the side of your house into a granary. woodlands, it also breeds in riparian, granary snags conflicts with the decline in Douglas-fir, redwood, and tropical Acorn woodpeckers also eat sap in early some areas of these habitat features. hardwood forests where , such as the spring if their acorn supply is gone. To get tanoak of coastal Oregon and , to the sap, they drill small holes in bark that Where to See are available. are larger, farther apart, and less linearly Acorn woodpeckers breed in Redwood NSP, Whiskeytown NRA, and Oregon Caves In the US, acorn woodpeckers occur in spaced than those made by NMP, and are occasional vagrants at Lassen Oregon, California, and the Southwest, but woodpeckers. Other foods include fruit, oat Volcanic NP. the species’ entire range goes down to catkins, flower nectar, and less commonly, grass seeds, lizards, and eggs (rejected northern South America. The northernmost More Information from their own nests!). of 7 subspecies, M. f. bairdi, is the Oregon https://www.audubon.org/field- and California variety. Reproduction guide/bird/acorn-woodpecker Acorn woodpeckers are cooperative Most acorn woodpecker populations are https://blog.nature.org/science/2017/04/24/ breeders, sharing in the care of young. year-round residents, leaving their core acorn-woodpecker-the-fascinating-life-of- Typically, a core breeder group of 1–7 territory only when food is scarce. the-master-hoarder/

EXPERIENCE YOUR AMERICATM Prep ared by Sonya Daw February 28, 2019