The calls of Carolina wrens enliven our yard each year. In the spring one decided to use the L-shape of our house to its mating advantage. It routinely sat on a woodpile by our front door in the corner of the L, making that area its private amphitheater or “courtyard.” The high-pitched “tea kettle, tea kettle, tea kettle” penetrated through the walls, giving us the sensation that it was living inside our home. And this is not the first Carolina wren to have discovered the superior acoustics of this location.
These birds have many different calls; the cheery, cheery, cheery song and the rattles are common as well. With dozens of different calls they continually confuse me. In fact, the Birder’s Handbook suggests that as many as 41 different calls have been identified. I love to use that as cover for my inadequacies in identifying even their two most common calls and rattle. One thing is evident: They are very vocal and aren’t afraid to broadcast live. They can be heard during daylight hours calling about a quarter of the time.
In a number of songbirds only the male holds forth, but both the male and female Carolina wren sing; they even perform duets. Their calls are territorial as well as serving the purpose of courtship serenades. While many birds are heard primarily in the spring, these wrens sing year round.
The species is considered to be medium-sized at about five to nine inches long. These measurements surprised me because I think of them as smaller, possibly because they often appear roly-poly in the mid-section, with a streamlined tail and very thin beak.
Their curved bill and raised tail are outstanding features. They switch rapidly between branches, often stretching their relatively long legs along a branch or between two twigs. When they cling to a tree trunk it is often with an impressive split—step aside, Simone Biles! Generally their flights are short, giving them a flitting-about persona.
The wren’s eyebrows are a vivid white extending from the bill to the base of the neck. The two-toned appearance of a rufous upper and buff lower body is distinctive. The rufous feathers give an impression of being spotted in a bar-like fashion.
The male is slightly larger than the female but otherwise they are essentially identical in appearance. The second largest wren in the United States, the species is exceeded in size only by the cactus wren.
In mid-July of last year, our suitor showed himself to have successfully reconnected with his mate, as evidenced by our courtyard being used by a family of wrens. The species mates for life. Their nests are cup-shaped and domed, constructed using a wide variety of nesting materials including found objects, pine needles, dead leaves, mosses, feathers, hair, string, dried grass—and they also have an affinity for shed snake skins.
Ornithologists have long theorized that snake skins may be employed by some birds to discourage predation. When researchers at Arkansas State University compared nests with snake skins versus those without, their results supported the theory that snake skins do deter an area’s dominant mammalian predators.
Wrens are well-known for making use of a wide variety of odd structures for nesting. Hanging plants, old woodpecker holes, eves of porches, old shoes, mailboxes, newspaper tubes, tin cans, garage shelves, propane tank covers, furniture, window sills, abandoned hornet nests, and endless other handy nooks and crannies are all popular choices.
The North American Breeding Bird Survey estimates global populations of select species and assigns conservation risk designations based on observed increases and decreases in a given population—trends in abundance. The Carolina wren’s adaptability to suburbia likely contributes in part to its being listed as of “least concern” or “low concern” in terms of ecological species indices.
Carolina wrens build a new nest for each brood and construction of the first one normally takes a week. In our area, a pair will generally raise two broods a year. Moving southward three are raised, and in odd cases four. Early nesting can begin in March, especially in southern parts of their range. This would enable a pair to have as many as 24 young in a season.
They are year-round residents of the eastern half of the United States, extending to Central America, the Yucatan, and Mexico. As a result, they are not considered migrators. Throughout the 20th century their range has expanded both northward and westward. In terms of preferred habitat they like the cover of shrubby woodlands.
One of “our” wrens often begins a nest in a cubby hole in our utility golf cart, which has given me quite the start when I’ve gotten behind the wheel. One year I found its pinkish-white spotted eggs in the nest along with the larger brown speckled-gray egg of a cowbird. Cowbirds are known as brood parasites, laying eggs in other birds’ nests and thus creating a surrogate state of affairs. The unsuspecting foster parents raise the larger bird, often at the expense of their own smaller young.
Last year’s courtyard family was adorable. The young fledglings were at an age where they had not lost all their downy feathers and looked as if they just had a bad hairdryer job at a slipshod salon. The young were taking turns begging on top of a post in our courtyard, while the parents made foraging trips to satisfy their insatiable appetites. While the female incubates the eggs and the male delivers sustenance, once the babies have hatched both parents forage for food to raise their chicks over a two-week period. Young are fed insects like caterpillars, crickets, and beetles.
The strategy employed in incubation is essentially synchronous, meaning the female does not sit on the nest until laying is completely finished. She begins incubation after the ultimate or last egg is laid, or on the second to last egg, called the penultimate egg. So even though the eggs are laid a day apart they will hatch at the same time; thus the resulting young are all the same size. There are records of their hatching asynchronously, but it is not as common.
I always look forward to seeing this talkative little denizen in our yard and soon I am hoping to catch a glimpse of one of their fluffed-up broods.
Sources
Animal Diversity Website, University of Michigan
Cornell Lab of Ornithology, All About Birds
AvianReport.com
Sialis.org
The Birder’s Handbook, Erhlich et al
