Make Birds Feel at Home With a Brush Pile

A bruiser of a thunderstorm roared through my neighborhood recently, tearing down countless tree branches and even some hefty limbs. Along with the mushrooms that sprouted after the soaking rain, the storm’s aftermath brought another sort of emergence: Dozens of brown paper yard waste bags, stuffed with debris, popped up along the curbs. 

Being cheap and slothful, I didn’t join my neighbors in buying bags, stuffing them with sticks, and paying my city government to come pick them up. (Not that there’s anything wrong with that.) Instead, I spent a few minutes gathering downed branches and twigs and threw them on my brush pile. Free, easy—sold.

There’s also a more virtuous reason to build a brush pile: It’s a supremely simple and effective way to make your neighborhood more welcoming to birds. 

“What these things become are little shelter spots for all sorts of wildlife,” says David Mizejewski, a naturalist with the National Wildlife Federation. “They become hunting grounds for all sorts of animals that are trying to find things to eat.” Mizejewski says even modest brush piles like those in his suburban New Jersey yard host a stunning variety of critters—birds, bugs, snakes, voles, groundhogs, foxes, and more. “Brush piles really do become almost like wildlife hotels.”

Wrens are particularly fond of brush piles, Mizejewski says, which checks out—I’ve seen Carolina and House Wrens bopping around the edges of the one in my yard. And they’re far from the only birds that will happily duck in to cool off in a heat wave, warm up in a snowstorm, or look for some spiders or seeds to nibble on. A variety of species that thrive in the shrubby transition zones between forests and meadows—flickers, nuthatches, cardinals, catbirds, and more—will find familiar comfort in a brush pile, he says: “This is the kind of thing that naturally forms in those edge habitats.”

So, how do you build a brush pile? Government wildlife managers recommend laying down a base layer of substantial logs—say 6 to 10 inches in diameter—arranged in a rectangle of 10 to 20 feet on each side, and with 6 to 8 inches of space between each log. Then build a second layer on top of that, using logs of slightly smaller diameter arranged perpendicular to the base. Next, pile on brush about three to six feet high, with bigger branches at the bottom and smaller ones on top. Leave the edges somewhat loose so that animals can come and go. Add a top layer with lots of leafy branches or pine boughs. Voila. 

That’s one option, anyway. You can build your brush pile by the book—literally, that’s how Mizejewski says to do it in his book—but he’ll let you in on a little secret: “Quite honestly, I don’t think the wildlife care.” 

The important thing is that the structure is dense enough to provide good shelter, with plenty of nooks and crannies for animals to tuck into. If you’ve got a sizable property with lots of trees, go ahead and build a big old sucker. If you’ve only got thin, shrubby material and no beefy branches, that’s cool. Pile it up and see who visits. Heck, even if you’re part of an HOA with persnickety rules, you might be able to get away with building a sculpture out of sticks that will satisfy the sticklers and still provide some wildlife benefits. Tell them I said it’s fine.

Your brush pile will naturally slump as the months pass. That’s good. All that decaying wood will attract ants and other insects that in turn will provide good meals for visiting birds. It’ll also enrich the soil with nutrients. Just make sure you keep adding to your pile to offset that shrinkage. Mizejewski recommends making it part of your spring and fall routine to add new material to the heap—pruned branches, downed boughs, whatever you’ve got. And if New Year’s Day arrives and you have a Christmas tree to dispose of, you know what to do. 

An important caveat: A brush pile is not appropriate for every site. If you have a yard in a city with lots of rats, for example, don’t build deluxe rat condos. If you live in a region where wildfire is a concern, you don’t want a pile of dry fuel near your house. But you’ve still got options. In the first instance, you can add native plants to help birds. In the latter, a rock pile provides many of the same wildlife benefits without the fire risk. 

Building a brush pile is just one way Mizejewski encourages people to rethink conventional notions of what a yard should look like. Rather than raking up leaves for disposal, for instance, keeping them on your property nourishes the soil—free fertilizer!—and provides habitat for birds, amphibians, and overwintering insects. (His organization has designated October Leave the Leaves Month.) Letting the stalks and seedheads of perennials remain through the winter, rather than trimming them in the fall, provides another good food source for birds. “The more we can keep that material on site, the more natural that space is going to become,” Mizejewski says. 

I did a bit of light pruning the other day, which gave me some good branches to add to my brush pile. I jammed their butt ends down into the heap and then broke them at 90 degree angles, such that they created a thick roof of leaves and pine needles. Then I stood back and looked at the pile awhile, and thought about the wrens and chipmunks and other characters that will hunker down in there when the weather turns cold and the snow starts falling. It felt good. I recommend it.