Dear Bird Folks,

We have a large open yard and would like to put up some birdhouses to attract Tree Swallows. My question is how large is their territory? If we put up several houses are we likely to get more than one pair?

– Tim, Freetown, MA

Good idea, Tim,

I like that you are putting up houses for Tree Swallows. With bluebird mania sweeping the country, it’s nice to hear that at least a few people haven’t forgotten about our swallows. Tree Swallows are very sweet birds and are every bit as handsome as bluebirds. Plus, they’ll eagerly come to manmade nest boxes, eat lots of annoying insects and are far more entertaining to watch. There are several other good things to say about Tree Swallows, but I don’t dare do any more swallow vs. bluebird comparisons. I don’t want to get all the bluebird people upset with me. As it is, I have numerous stork lovers mad at me and if I alienate the bluebird crowd, too, I’d have to move to another state, any state. Well, any state except Rhode Island. Several elderly stork lovers from RI have put a contract out on me and I don’t dare cross into Little Rhodie until they calm down, which may be never.

As the name implies trees are important to Trees Swallows. But the trees they covet are dead trees, ones that have been used by woodpeckers. As is the case with bluebirds, Tree Swallows need a cavity in which to build their nests, and just like bluebirds they have absolutely no carpentry skills. Woodpeckers, on the other hand, have enough skills for two birds. They hollow out their own nest cavity and once they’re finished using it, they’ll donate it to any bird that needs it, with no compensation. Although I hear they do get some tax benefits.

Tree Swallows are fairly common summertime birds in our area. However, they are not typical backyard birds, unless your backyard happens to be a farm or large field. If you do have a large open yard, you stand a good chance of getting these birds. Tree Swallows are gregarious and don’t bother defending much of a territory. While they’ll fight like rabid badgers to defend the nesting cavity they have claimed, it’s fine with them if another swallow wants to live in the dead tree next door. Another cool thing about Tree Swallows is that they don’t mind people. If there aren’t any natural tree cavities available they’ll readily come to inexpensive bird boxes. The key word here is “inexpensive.” You won’t need to buy one of those large trophy homes that Purple Martins require, or build a barn like Barn Swallows demand or own a bank, which is mandatory if you want to attract Bank Swallows. Tree Swallows are simple folk and a basic box is all they want.

Although Tree Swallows like their boxes to be simple on the outside, they like it fancier on the inside. In addition to the typical nesting material, they have a little secret. Tree Swallows have a feather fetish. They love to line their nests with feathers, especially white feathers, and no one is really sure why. Some researchers have suggested that it has to do with camouflage or insulation. If Freud were a birder he may have proposed that these little birds harbor a latent desire to be swans. (Sigmund sure had some wacky ideas.)

Even though this feather thing might seem insignificant to us, the swallows are consumed by it. They will sometimes fly for miles in an effort to locate white feathers. Finding the right feathers is challenging enough but getting them back to the nest can be even more difficult. Neighboring swallows will often rise up and try to steal feathers from a bird returning home. This leads to dramatic aerial chases, with the feather-carrying bird being pursued by several others. Once the chased bird makes it into its cavity the whole event should be over, but that’s not always the case. Sometimes the pursued bird reemerges from the cavity and continues to fly around with its prized feather, inviting the other swallows to chase it again. And if the others have lost interest in the game, the bird will drop the feather in hopes of sparking their interest once again. It is very similar to what dogs do when they want one of us to toss a tennis ball to them, only there isn’t nearly as much drool involved with the swallows.

I don’t know how much land you have, Tim, but Tree Swallows really like to be out in the open. The further you put your nest boxes away from living trees and buildings, the happier they’ll be. As I said, their territory is minimal so spacing them every thirty feet apart should be fine. I encourage people to put up lots of birdhouses, and it’s not just because I sell birdhouses (although that has something to do with it). Besides swallows and bluebirds, chickadees, titmice and nuthatches will also use birdhouses. The more boxes, the more birds you are likely to attract. If you cheap out and only put up one box, you could end up with lots of birds squabbling and fighting, and you don’t need that. There’s enough squabbling and fighting in the world already. I’m talking to you, stork lovers in Rhode Island.