Identification of Wrentit and Similar Songbirds

Author’s note: As I stand in for Kenn Kaufman as he works on a book project, I would like to acknowledge his stellar role in sharing with birdwatchers of all experience levels his wealth of knowledge in natural history, especially the identification, status and distribution of birds and the history of birding. My birding experience is largely centered on California and adjacent areas, more restricted than Kenn’s vast geographic wisdom. And while my future articles on “ID Tips” will be relevant to readers all over North America north of Mexico, my initial effort here deals with a bird you’ll probably never see far from the coastal slope of the Oregon, California and Baja California to the northwest.

This column focuses on a bird confined to the Pacific states from extreme northwest Oregon just south to Baja California. It is not prone to wander, so it is unlikely to be seen outside its well-defined range. So why is the Wrentit of interest to bird watchers in the remaining 90% of North America? Certainly, its uniqueness and its interesting evolutionary and biogeographical history play a role. And it’s not a slam-dunk identification; the bird is an indescribable skulker, superficially combining – as its name suggests – the characters of different small songbirds. The general brownish coloration, affinity for dense brush, and habit of cocking its tail is reminiscent of many wrens. Strong legs and a fairly short beak with a slightly down-curved culmen are reminiscent of tits and tits. Even within its range, observers frequently confuse other species with it, which can cause headaches, as records just a few kilometers from range or habitat would be very important.

The Wrentit is surely a “light brown work”, but closer inspection shows the intricacy and beauty of its colors and patterns. The breast has a pinkish tinge, subtle streaks line the underparts, and the bird has a fixed whitish iris. Males and females are essentially identical; juveniles are best distinguished by subtle differences in the color ring around the white iris.

Detecting and identifying the Wrentit begins with its vocalizations. In the words of William Leon Dawson, the Poet Laureate of California Ornithology, “Indeed it is safe to say that the bird is heard a thousand times for once it is seen.” The male’s song is a classic “bouncing ball” pattern consisting of several peep notes which then rapidly accelerate into a loose trill. The female song, often in duet with the male, is a slower series of single notes that do not speed up. The songs are audible for some distance through the brush-covered hills. Up close, you’ll hear the common call – a series of rapid purrs of atonal notes.

Much of what we know about the life history of the Wrentit comes from the studies of Mary M. Erickson. A student of Joseph Grinnell, she conducted detailed work in the 1930s near the campus of the University of California, Berkeley. Long-term banding studies in Marin County, California have provided much more detail. Slight range expansions in recent decades may be due to the enlightened replacement of barren turf with native and other drought-tolerant shrubs in residential areas and an expansion of shrubby habitats as a result of intensive commercial logging. But work by Michael Soule and his colleagues around San Diego has shown how habitat fragmentation by urban development has also caused the loss of some populations.

Wandering among birds is full of surprises. It is increasingly clear that almost all species of birds can wander ‘out of range’, which is especially true for many migratory species. But if you’re birdwatching east of the Pacific states, don’t hold your breath for a wandering Wrentit. Extreme sedentary behavior is a characteristic of these birds, which can spend their lives in real estate not much larger than a football field.

Wrentit, October in Los Angeles County, California. Photo by Brian E. Small

Although this Wrentit is native to the same region as the bird in the photo on the left, it is overall a little more brown (less grey), possibly due to a combination of lighting and individual variation. This gray to reddish-brown spectrum is also reflected in the geographic variation of Wrentit; the reddest birds are found in the species’ northern coastal range in Oregon and northern California and the palest and grayest birds are found in the interior and south. There are five generally accepted Wrentit subspecies based on plumage color and, to a lesser extent, tail length. But, as with so many named bird subspecies, some of them represent attempts to fit continuous and often subtle variation into discrete taxonomic units.

Wrentit. October in Los Angeles County, California. Photo by Brian E. Small

Subtle at times, but more evident in many views, the streaks across the underparts of the Wrentit distinguish it from other small, dull gray or brown inhabitants of the extensive shrubby habitat such as Bushtits, wrens and gnatcatchers, all of which lack these longitudinals tracks. Such a feature can be difficult to observe in the intricate shadows and obscuring branches in which the Wrentits hide, but the patient birder is sometimes rewarded with more open views like this. Note that the rather “hinged” tail is usually held at an acute angle – during the Wrentit’s short flights the tail is pumped up and down, as if helping the short, rounded wings to keep the bird aloft .

Wrentit. October in Los Angeles County, California. Photo by Brian E. Small

It’s not often you’ll see a Wrentit out in the open on a rock like this. It is a bird that has a penchant for staying in the dense, stiff vegetation of chaparral, sage scrub, and the understory of oak and riparian forests. Nevertheless, descriptor William Gambel gave this bird the English nickname “Ground-Tit”, because they often drop to the ground under their shrub coat to feed among the leaf litter. And the generic name chame comes from a Greek root meaning “on the ground”. One could facetiously affirm that a key character of identification of the Wrentit is the difficulty one experiences in seeing one! And this challenge highlights the importance of learning their frequent and distinctive calls.

Bewick’s Wren, adult. April in San Diego County, California. Photo by Brian E. Small

It is taxonomically neither “troglodyte” nor “tit”, but the name of the Wrentit acknowledges its superficial similarity to these two groups. On the west coast, the Bewick’s Wren, like the one pictured here, almost inevitably shares the scrubby habitat of the Wrentit, and the two species are often in close proximity. Like the Wrentit, it is a rather uniform gray and brown bird that often holds its long tail erect. But the similarities end there – the wren shows a bold white supercilium, dark eye, black bars and white feathering on the tail, and black bars on the undertail-coverts. And note the long, slender beak of the wren.

Bushtit, adult female. October in Los Angeles County, California. Photo by Brian E. Small

The “tit” part of “Wrentit” once again refers to a superficial morphological similarity with the chickadees and chickadees of the family Paridae. But perhaps the most similar “tit” species, and a closer cousin to the Wrentit than the parids, is the Bushtit. Long-tailed and plain grey-brown, with an equally sturdy beak, the Bushtit’s appearance (and name) can be confused with the Wrentit. Adult female Bushtits, like the bird pictured here, have whitish eyes, just like Wrentits. But the smaller Bushtits almost always travel in groups – even in the dozens – and fly easily through open spaces between trees and shrubs. They are extremely acrobatic, often hanging upside down or upside down. And they maintain a constant chatter of sweet “pit” notes unlike all Wrentit vocalizations.

California gnatcatcher, female. June in Los Angeles County, California. Photo by Brian E. Small

Although localized and of conservation concern, the California Gnatcatcher is another relatively nondescript grey-brown skulker in dense scrub vegetation that shares part of Wrentit’s range on the southern California coastal slope. Black-capped breeding males are distinctive, but simpler females with brownish plumage tones may be reminiscent of a Wrentit. Like the Wrentits, they are usually found in pairs and are often well settled in expanses of sage and other shrubs. But these gnatcatchers have a thin white eyering (the eye itself is dark), a very thin beak and a blackish tail with some white at the corners; they have no trace of streaks on the chest. And the calls are very different – ​​soft growls and a distinctive kitten-like meow.

Rank the Wrentit

In 1845, William Gambel first described the Wrentit to science as a little bandaged, linking it to chickadees and chickadees, as well as a few other small insectivorous birds. Barely two years later, Gambel recognized its singularity by erecting the genre chame for that. The Wrentit resided in its own family (Chamaeidae) for many decades. But even as early as the second half of the 1800s, several renowned ornithologists recognized that it might have its roots among the “Timeliidae” (now Timaliidae) – a diverse Old World group known as the babblers – and this has was confirmed by Charles Sibley and Jon Ahlquist’s DNA-DNA hybridization studies in the early 1980s.

More recent comprehensive genomic work has clarified the relationships within the “talkative assemblage”, bringing into the talkative fold a group of “Old World Warblers” (Sylvia and relatives) as well as Asiatic parrots (often placed in the family Paradoxornithidae). The current taxonomy retains a segment of the babbler radiation, including the Wrentit, Sylvia warblers, parrots, and a few relatives, in the family Sylviidae, while other relatives among the babblers remain in the family Timaliidae (with other related families in the babbler radiation, all in Asia and other other parts of the Eastern Hemisphere). No matter where these lines are drawn, it is clear that the ancestor of the Wrentit colonized the Americas via the Bering Land Bridge, as all of his relatives are exclusively from the Old World.