Today we take a look at some totally socialist birds. Such complete flaming lefties that I'm pretty sure their scientific name "Melanerpes formicivorus" translates as "community organizer". They even wear little Che Guevara style red berets!
I speak, of course, of the ACORN Woodpecker. Yes, I know your field guide doesn't bother to properly capitalize their name, but that doesn't disguise the essential nature of these little avian activists. Let’s save RedState some trouble and get to the bottom of their story here.
Acorn Woodpecker, making a speech about Single Payer Healthcare. (Teleprompter hidden by podium.)
This diary is a reprint of "Soros Sent 'Em" from August 2009... more about that at the end.
(I will leave snark to the pros and revert to my usual self ...)
As their common name suggests, this wonderful western species is closely tied to oak woodlands, though they can be found in other areas as long as oaks are present in sufficient numbers. Acorns are only half the story, though. As their scientific name suggests, they are ant-eaters as well (you do read Latin, don’t you?... formici = ants + vorus = eating) They eat flying ants and other insects, as well as sap and nectar, during much of the year with acorns providing food during the lean months of winter.
Many birds cache food for the winter, but few others work collectively to do so. As far as I know, they are the only North American species that does so – if anyone knows of other species who do so elsewhere in the world, please mention it in the comments. (They like eating ants, and they’re eating like ants – building a storehouse of food that they can draw on later.) Even before you see a bird, you’ll know they’re in the area when you spot one of their acorn granaries.
Acorn granary - Woodpeckers excavate holes and stuff acorns into them for storage. Though granaries are usually made from trees, they will use other structures as well, such as telephone/power poles and buildings (something that has caused major problems with some property owners – more about that in the comments).
As acorns ripen and fall, acorn woodpeckers gather them off the ground and bring them to their storage areas. They’ll sometimes push them into crevices in bark, but they normally store them in holes that they’ve drilled just for that purpose. A lot of labor goes into creating the granary trees, which can store tens of thousands of acorns. The creation and maintenance of granaries couldn’t occur without the cooperation of a large family/flock to drill the holes, gather the acorns, and defend against other creatures that might want to raid the bounty. By working together, they gain a measure of food security for all... the little socialists.
Granary tree - Because of the amount of labor that goes into creating a granary tree, they will be reused year after year, sometimes even after the tree has fallen.
I've read that they don't just store the acorns - they actually "farm" some of them. Apparently, some of the acorns are allowed to be infested by beetles, which lay their eggs inside. The larvae "ripen" at roughly the time that nestlings need a lot of insect food, and the woodpeckers harvest them to feed their chicks. (I'm on dialup, so haven't had time to find the link - if I can get it, I'll add it.)
Their strong bonds as a community extend into other areas of their lives besides food. In many areas, Acorn Woodpeckers are known to nest communally. Not just nesting colonially like swallows or herons – who have groups of nests clustered together – but communally, as in sharing the same nest cavity. (Some also have individual nests.)
Female (l) vs. Male (r) Acorn Woodpeckers. The red in females' crowns is separated from the white forehead by a wide black border; males' red crowns meet the white with no border. This male could use some Universal Dental Care - his bill is overgrown and crossed. He seems to be doing okay, as he's been here all year. Maybe having access to a feeder helps, or maybe he can survive better as a result of being part of a community?
It’s not entirely peace and happiness, as one account that I read describes it:
Generally, Acorn Woodpecker groups contain 1-7 male breeders that compete for matings with 1-3 egg-laying females. In groups that contain more than one female breeder, the female cobreeders lay their eggs in the same nest cavity. There is often extreme reproductive competition between joint-nesting females, who regularly destroy eggs laid by their cobreeders. After females have established a normal laying sequence, egg destruction stops. Reproduction competition between males is displayed by attempts by a male to disrupt copulation between another pair. Courtship and pair-bonding displays are absent.
Male feeding baby in nest cavity. Photo by Eugene Zelenko, via WikiCommons
I first got to know Acorn Woodpeckers when we started coming to our cabin 25 years ago. Although the area is primarily second-growth redwoods, there were many oaks and madrones in the mix. The area had been logged in the ‘teens and 20’s, so the trees were 60-70 years old at that point. Immediately after logging, oaks and madrones shoot up and do quite well among the many spindly redwood saplings. All of those oaks encouraged acorn woodpeckers to move in. At the end of our street, there was an acorn granary built in the bark of a cluster of redwoods.
At a certain point, the oaks and madrones stop growing, but the redwoods continue to reach skyward, stealing sunlight from the others – something that was happening around the time we started visiting. The oaks began to die off and the woodpeckers had to move on, because there weren’t enough acorns to sustain the colonies any longer. For ten or more years, their wild “Whack-up! Whack-up! Whack-up! Whack-up!” call was missing from the neighborhood.
Woodpecker launching from tree trunk.
In the last few years, they’ve started to drift back. People are worried about keeping defensible space around their homes, so they’ve removed some trees – allowing more light to reach some of the oaks and madrones. Things really picked up last year... I suspect some of our birds were pushed from other areas by fires. We’ve had a small group visiting the suet feeder I put out during our visits. I know there are at least two males (including the one with the odd bill shown above) and at least three females; I’ve seen as many as seven of them at once, though not close enough to sex them all. It seems like we have enough to establish a small -colony- commune... fingers crossed.
So we're heading down to our cabin this weekend for the first time this year. I'm not sure if I'll have internet access or not... dial up is more complicated than it used to be, now that I don't have my old Windows machine. If you're seeing this note that I'm writing on Saturday morning, it means I couldn't get online to edit. Which means two additional things: I won't be around to see/tend the diary until mid-day when we get home, and I'll be looking for guest hosts for some of these summer weekends (including next weekend). If you're interested in hosting, drop me a KosMessage.