Acorn Woodpecker Sightings on Island is Good News

Sean Feeney A female Acorn Woodpecker stores an acorn in a palm tree.

Acorn Woodpecker Sightings on Island is Good News

Melanerpes formicivorus (genus of woodpecker, anteater)

It was a grim day in the early 1980s when I witnessed a starling pulling an adult Acorn Woodpecker out of its nest hole in Lincoln Park. Starlings then groomed and used the hole for their nest. The woodpecker did not survive the struggle. Competition from others explained, in part, the reduced numbers of a wonderful bird that was iconic to Alameda, harvesting acorns from a mature live oak forest (or Encinal), like so many other species. Alameda’s indigenous people also knew the value of acorns as a food source. The starling incident alerted us to a decline of Acorn Woodpeckers in Alameda. Once common, only rare occurrences were now recorded: 1989 (3), 1993 (1), 2001 (1)

Then on Nov. 20, 2021, up to five were seen storing acorns from the oaks at Washington Park into pockets of the pruned fronds of our family’s curb side palm tree. This didn’t seem possible. Another observer saw one the same day in his yard’s live oak some distance away. A mixture of joy and confusion settled in. The birds continued their busy work for days. Local birders could only hope that Acorn Woodpeckers would return to create entertaining colonies in our parks, or at least remain until December’s Christmas Bird Count. Could this be possible?

Crows took notice of the active woodpeckers and began collecting acorns too but stored them in some unknown location to the south. Crows could be trouble. Activity at the palm tree granary quieted. It seemed this group might be a temporary unexplained delight. Suspense, worry, and hope became uncomfortable companions.

Acorn Woodpeckers are one of several woodpeckers seen in Alameda. As a species it has a wide geographic range. Varieties have evolved at many latitudes from Canada to Columbia and have extended habitats as well, suggesting it is an adaptable species.

As an adult local Acorn Woodpeckers have distinctive white eyes (young have blue eyes). They range in length from 7.5 to 9.1 inches. They range in wingspan from 14 to 17 inches. They can weigh between 2.3 to 3.2 oz. Face, forehead, and upper breast are white with a few black feathers around the bill. Head and nape are black with a bright red cap on males and similar for females, but with a black band above their white face reducing the red cap. Their back is black, and their rump is white. In flight wings display white patches.

The most common call is described as “waka waka” repeated several times, but they have a much larger vocabulary. The “waka” call resembles laughter and is one of the reasons Walter Lanz chose to create a stylized cartoon of the Acorn Woodpecker. Woody Woodpecker became so popular it had an Oscar nomination and is honored with a star on the pavement of Hollywood Blvd.

Their diet is primarily insects and acorns (53% of diet in one California study), but the list on their menu is long including fruit, sap, bats, lizards, and more. They visit hummingbird feeders and eat bananas in the tropics. They are skilled at fly-catching insects, including breeding ants and termites. Storage behaviors of these master hoarders are very interesting. Consider one fallen tree was found to hold over 60,000 acorns. Social behaviors are also complex with unexpected communal interactions and family relationships.

We can only hope that this “full of surprises” woodpecker remains a part of our community. Having a palm tree granary is one happy surprise for us. We continue to watch and learn from their industrious efforts to prepare for the future.

Yes! Two Acorn Woodpeckers were found during Alameda’s 2021 Christmas Bird Count after a 20-year absence. Good news, indeed!

Leora Feeney is a member of Golden Gate Audubon Society and co-chair of its Friends of the Alameda Wildlife Reserve conservation committee.