Acorn Woodpeckers Melanerpes formicivorus

Guadalupe Oak Grove Park, California.
16 June 2006

Found from northwestern Oregon, California, the American Southwest, and western Mexico through the Central American highlands and into the northern Andes of Colombia, the beautiful (and noisy) Acorn Woodpecker prefers mixed pine-oak woodlands where oak trees are plentiful (including urban parks and suburban areas that possess numerous oak trees). Highly social Acorn Woodpeckers usually live year-round in social units. The species is generally sedentary, but there are some migrant populations in areas where there are large seasonal fluctuations of insects.

One of the few woodpecker species I’ve ever seen ‘flycatching’, Acorn Woodpeckers often sit at the tops of trees looping into the air on broad wings after various species of flying ants and other Hymenoptera and Coleoptera (the specific name formicivorus translates as ant eater). Their main diet consists of insects, sap, oak catkins, fruit, and flower nectar: however, as its English name suggests, acorns are critical for their winter survival, and Acorn Woodpeckers are renowned for storing nuts in individually-drilled holes in what are termed ‘granaries’.

Dotted across open woodland, granary trees may have as many as 50,000 holes drilled into them. The holes are usually drilled into dead limbs and in thick bark during the winter, and any dead or living tree with deep dry bark can be used as a granary. Studies have apparently shown that these granaries are so important that they are one of the main reasons why Acorn Woodpeckers live in such large families, at least in California: only a large group can collect so many acorns and also defend them against other groups.

The birds below were photographed in Guadalupe Oak Grove Park (McAbee & Thorntree, south of Coleman near Almaden Expwy) near San Jose, which protects an unmodified remnant patch of oak woodland surrounded by housing developments.

(For more information please go to Animal Diversity - Acorn Woodpecker.)

All photographs copyright Charlie Moores.

 

(*And - just in case you were wondering - the title of this post is a very abstruse reference to the Beatles song “A Day in the Life” (on their seminal Sgt. Pepper’s Lonely Hearts Club Band album) which includes the line “four thousand holes in Blackburn Lancashire”. The lyric was suggested by an article in the Daily Mail for Jan 17th. 1967 which mentioned that: “There are 4000 holes in the road in Blackburn Lancashire, one twenty-sixth of a hole per person, according to a council survey. If Blackburn is typical then there are over two million holes in Britain’s roads and 300 000 in London.”
And people think that 10,000 Birds is just about, er, birds…)