Making a home for Carolina wrens

Sometimes a simple act can produce significant results.

About a year ago I explained how to provide a winter roosting site for Carolina wrens — small, handsome birds marked by chestnut above, cinnamon below, and a prominent white eye stripe. They spend most of their time in dense vegetation, and are more often heard than seen. The song is a loud, ringing, musical whistle that can sometimes be heard in midwinter. Usually it’s a series of triplets — “Tea kettle! Tea kettle! Tea kettle!” or “Chirpity, chirpity, chirpity!” They are common around homes and often explore sheds, barns and open garages.

In fact, it’s the Carolina wren’s affinity for nooks and crannies that first brought it to my attention. Though classified as cavity-nesters, Carolina wrens usually forsake tree cavities and nest boxes in favor of more unusual nest sites. Over the years I’ve found their nests in mailboxes, cans of nails, old boots and a clothespin bag. Three years ago they discovered a 1-gallon bucket hung on a hook just outside the side door to the garage. Protected from above by a porch, it was completely weatherproof.

Over the last two winters, I also discovered that wrens were using the bucket as a nighttime roosting site. The nesting material, which I hadn’t removed, provides adequate insulation, and every evening at dusk the wrens slip into the buckets.

On one occasion I watched two individuals retire to a single bucket.

The key is to keep the buckets under a roof so the insulating vegetation cannot get wet from rain or snow. I now have three buckets on porches, two in sheds, and the original one at the garage. In the buckets that didn’t contain old nests, I simply added a handful of dried grass and leaves and formed a small cup with my fist. The birds took right to the roosting buckets; they now use four of the six buckets every night.

This simple discovery could have a profound impact on Carolina wren survival. They are southern birds that expand their range northward during years of mild winters. The winters of 1977, 1978 and 1993 were brutal and killed off the Carolina wrens in temperate states such as Pennsylvania, West Virginia, Ohio, New York and Michigan. After each of these hard winters, it took years for wren numbers to rebound.

Since watching two Carolina wrens slip into a bucket one evening two years ago, I’ve wondered if pairs frequently sleep together. So over the last few weeks, I’ve checked each of the buckets just before dawn on chilly mornings. Since it was just minutes before daylight, I figured the disturbance wouldn’t be disruptive. And sure enough, two individuals flushed from each bucket I checked. Not only do Carolina wrens use the insulation provided by the dry vegetation in the buckets, they also generate and conserve their own body heat by sleeping in pairs. It’s gratifying to learn that something as simple and cheap as a plastic bucket can be a valuable conservation tool.

Presently, Carolina wrens are quite common here on the ridge, and have been since the late 1990s. When the next hard winter strikes, they will surely disappear again — unless the factor limiting their survival is finding a suitable place to stay warm and dry during the night. If that’s the case, a simple bucket hung under a roof might be just enough to get them through a cold snap or an ice storm.

You can also help Carolina wrens survive the winter by providing food. Though they are not seed-eaters by nature, mine have learned to eat shelled nuts and sunflower kernels. Wire mesh tubes are ideal for offering these foods. The birds cling directly to the mesh and remove one piece of food at a time.

Wrens also eat suet and live food — mealworms. They actually prefer mealworms to nuts, but competition is intense from woodpeckers, chickadees, titmice and nuthatches. Wild bird stores and bait shops sell mealworms, and you can find them online by googling “mealworms.”

XSend questions and comments to Dr. Scott Shalaway, R.D. 5, Cameron, WV 26033 or via e-mail to sshalaway@aol.com.