Ladder Pattern: Woodpeckers of the Mojave Desert
I do a lot of bird identification with my ears, which makes it nice to work with the window open. I'll be untangling a paragraph or waiting for my browser window to load, and half of my brain will note the pitched hummingbird battle going on outside; a good reminder that there are more important things than work. I've gotten so I can identify some birds by song faster than by appearance. But a high-pitched chirp I heard about three weeks ago stumped me. It seemed familiar, but I couldn't quite place it. So I got up, walked out to the kitchen, and surprised a ladder-backed woodpecker in the act of raiding our hummingbird feeder.
I'd heard of other birds using hummer feeders before, orioles and chickadees especially, and I have seen housefinches learn to get at the sugar water as well, but woodpeckers at hummingbird feeders was new to me. Some naturalist I am. Turns out it's a thing. A lot of species of woodpeckers seem to be attracted to hummingbird feeders. Apparently the ladder-backed is no exception.
You can buy hummingbird feeders that aren't accessible to woodpeckers, but where's the fun in that? I don't mind refilling the thing more often. It's only sugar and water, after all. But I did hang some woodpecker suet in a tree close at hand just to offer the ladder-backed a bit of variety, and he seemed to like it, and he brought a female friend along the day after I hung the suet cage.
Ladderbacks are smallish woodpeckers, six or seven inches long, with a distinctive pattern of black and white horizontal bars on their backs. Hence the name. Males have a distinctive woodpeckery red patch on their heads. Though they're closely related to the coastal Nuttall's woodpecker, which lives in oak savanna and coastal forests, ladderbacks are almost exclusively a bird of the desert, at least in the U.S. part of their territory. They range from the Antelope Valley through the desert southwest to Texas, and south to Central America -- where they shift from desert landscapes to pine forests as their preferred habitat.
Though it's not considered a common bird anywhere, the ladder-backed woodpecker is probably the most common woodpecker in the Mojave. Northern (red-shafted) flickers would be the only other candidate for the title, and I've seen them in a number of places in the Mojave where there are no ladderbacks, but it seems to me that flickers stick to higher altitudes a bit more than ladderbacks.
Pretty much any other California woodpecker you might name -- Nuttall's, acorns, downies, hairies -- doesn't seem get more than a few dozen miles into the Mojave Desert, though you do hear reports of confused vagrant coastal woodpeckers showing up at ponds and such. The Gila woodpecker, a favorite among birders in the Sonoran Desert section of Arizona, edges into the Mojave only along the Colorado River near Needles, though there are reliable sightings just outside the Mojave at Corn Springs, and a lot of sightings have been reported throughout Imperial County.
Flickers tend toward a yellowish tan overall color, which means that deep in the Mojave, if you see a woodpecker that looks like a woodpecker -- black and white feathers, possibly with a red cap -- it's almost certainly a ladder-backed.
Ladderbacks nest in cavities that they, or previous woodpeckers, have excavated in trees. They'll also choose existing holes caused by other animals or physical injury and enlarge them. In much of the desert there aren't a whole lot of trees to choose from that you can excavate a hole in, at least not a hole big enough to fit woodpeckers in. The woodpeckers are also non-migratory: they tend to find a place they like, with suitable breeding and feeding possibilities, and then they stay there. This means that across much of the southwest, ladder-backed woodpeckers tend to be found in or near forests of Joshua trees and saguaro cacti, which have the most capacious trunks in the desert. They're also a lot easier to hollow out than harder-wooded trees like junipers and piñons.
The birds feed almost exclusively on insects and invertebrates in the wild, along with the occasional cactus fruit, though as demonstrated in my backyard they'll also happily drink sugarwater and eat peanut butter suet. They can be pretty resourceful about finding insect food. About a decade ago I watched as a ladderback batted a fallen Joshua tree fruit around like a cat with a toy ball. Woodpeckers in general don't seem particularly playful, so I was slightly confused until I remembered that each maturing Joshua tree fruit has at least one caterpillar in it, a result of the trees' reproductive partnership with yucca moths. The woodpecker hammered at the fruit until it broke open, and a number of Joshua tree seeds fell out in the process, making the ladderback a potential vector for seed dispersal for a tree that desperately needs seed dispersal.
Of course like the Joshua tree's likely main seed disperser, the desert woodrat, ladderbacks don't offer much in the way of long-range help, as they stick close to their relatively small home territories. That's okay by me: their home-body nature means the mated pair of ladderbacks we have at out feeder this month may bring their family along in the months to come.
Chris Clarke is an environmental writer of two decades standing. Director of Desert Biodiversity, he writes from Joshua Tree regularly at his acclaimed blog Coyote Crossing and comments on desert issues on KCET weekly. Read his recent posts here.
