At the beginning of December, I noticed a fairly large brown bird (a little smaller than a crow) with black speckles on its back, pecking in my garden. It continued in the same spot for some time until it had made a hole in the soil maybe 5 cm in diameter. I wondered what it was up to.
I was fairly sure that the bird in question was a flicker, but I didn’t know much else. After the bird finished digging, I started digging. It reminded me of the physicist Richard Feynman whose father told him that knowing the names of things doesn't tell you about the thing.
What’s in a name?
Feynman did admit that names can be helpful when talking to other people about a subject, and that’s true for the Northern Flicker. Here’ is a picture of a Northern Flicker on Flickr. It gets its name from one of the sounds it makes, a repeated “flicker” or “wicka-wicka-wicka” sound, though I don’t think I would recognize the actual sound from those descriptions. Its scientific name is Colaptes auratus. Colaptes means “to peck.”
The Northern Flicker can be found over much of North America, in two subspecies: a red-shafted form in the west and a yellow-shafted subspecies in the east and north. They interbreed in areas where their populations overlap. I didn't know about these differences and didn't notice the details of colouring on the one in my garden, but I assume it was a red-shafted flicker, because they're found in Vancouver. The males have a red moustache, but I don't recall seeing that (though I wasn't looking for it), so maybe it was a female.
On the tip of the tongue
The flicker is a type of woodpecker, but it pecks soil instead of wood, mostly feeding on ants and beetles, but also other insects, berries and seeds. When I went out to look at the hole it had made, I saw an ant staggering out of it. A flicker's beak is narrower and more curved than other woodpeckers. Woodpeckers generally have disproportionately long tongues that wrap around their skull under the skin, ending in the right nostril. Flickers may have the longest tongue among North American birds, extending 5cm beyond the tip of the beak (rather like the Gene Simmons of birds). Many woodpeckers tend to have barbed tips on their tongues, but the flicker’s tongue is flattened with extra sticky saliva for picking up ants.
Flickers not only eat ants but they do something called anting. This mysterious behaviour has been observed in more than 200 bird species, but not adequately explained. Passive anting involves lying on top of an ant hill and letting ants crawl through their feathers. From a distance, it might look like a bird is sunning itself. Active anting involves picking up individual ants and rubbing them on their feathers. Again, from a distance, it might just look like they are preening their feathers. But on closer inspection, they are using ants, or sometimes other creatures—even cigarette butts! Northern Flickers have been seen performing both types of behaviour.
Anting is most often observed late in the summer or early fall, corresponding to a time when many birds moult. And these ants may provide some kind of relief to irritated skin. I don't think any human spas have implemented this yet.
Some ants produce formic acid in concentrations greater than 50%, which may help kill bird pests. Birds may rub ants on their feathers to kill feather mites or skin lice, perhaps an example of tool use in birds.
Another possible reason for active anting is that birds are removing the formic acid from the ants so they are more palatable when eaten.