Le Conte's Sparrow by Barry Van Dusen
Once again, Bird Observer offers a painting by the artist who has created many of our covers, Barry Van Dusen. Barry, who lives in Princeton, Massachusetts, is well known in the birding world. Barry has illustrated several nature books and pocket guides, and his articles and paintings have been featured in Birding, Bird Watcher’s Digest, and Yankee Magazine as well as Bird Observer. Barry’s interest in nature subjects began in 1982 with an association with the Massachusetts Audubon Society. He has been influenced by the work of European wildlife artists and has adopted their methodology of direct field sketching. Barry teaches workshops at various locations in Massachusetts. For more information, visit Barry’s website.
Le Conte's Sparrow
The Le Conte’s Sparrow (Ammodramus leconteii) is a small cryptic denizen of wet grasslands, sedges, and marshes. In winter Le Conte’s Sparrows are found in old fields and prairies, where they stay low and are difficult to see. If flushed, they fly low over the grass for a short distance before dropping out of sight. They also often walk through dense vegetation, avoiding observers. Because of their cryptic behavior, the basic biology and natural history of Le Conte’s Sparrows is poorly known. Although the species was first described in 1790, its nest was not discovered until nearly a century later.
Adult Le Conte’s Sparrows have a distinctive head and face pattern, a narrow white stripe splitting the black crown, and a bright buffy eye stripe and malar stripe separated by a brownish cheek. The upper breast, nape, back, and flanks are buff marked with fine to heavy dark brown to black streaks. The lower breast and belly are light gray. Le Conte’s Sparrows can be confused with Grasshopper, Baird’s, Henslow’s, Nelson’s, and Saltmarsh sparrows; however, the head and face pattern of Le Conte’s Sparrows is distinctive. Juveniles are somewhat muted versions of adults. The Le Conte’s Sparrow is monotypic with no subspecies recognized, and no geographic variation in their measurements, plumage, or song. They are closely related to other species in the genus Ammodramus.
The breeding range of the Le Conte’s Sparrow consists of a swath across west and Central Canada and into the United States from North Dakota east to the Great Lakes. They have a patchy distribution across eastern Canada occurring only where suitable wet habitat is available. This species is migratory and winters along the Gulf Coast from the Florida Panhandle to south Texas, where the greatest densities are reported, and also inland to Illinois. The specific distribution of this hard-to-see species is poorly known. In Massachusetts Le Conte’s Sparrow is considered a vagrant but since the 1980s the number of fall migrants observed appears to be increasing and there are currently at least 20 state records. Most occurrences have been recorded in October.
Le Conte’s Sparrows are apparently monogamous, but like many other facets of their life, their breeding biology is poorly known. The male’s song is a grasshopper- like buzzing, rarely given from an exposed perch. The call note is a shrill tsip and in nonbreeding season they communicate with a high, thin ssisst. During courtship the male gives chips and slurred notes as he ascends to 15-20 feet in the air, followed by the typical buzz notes as he descends on fluttering wings. Song probably functions as both territorial advertisement and mate attraction. Although apparently territorial, there is little known about the species’ agonistic behavior.
The preferred habitat of Le Conte’s Sparrow is marshy meadows and bogs. Nothing is known about pair formation, nest-site selection, or nest building. The nest is a cup composed of grass and rushes and is lined with fine grass or hair. The clutch is four to five greenish or grayish eggs, spotted with darker colors. There is no information on development of brood patches or incubation other than one observation at one nest that the female alone incubated for the first few days. The incubation period for one egg was 13 days. The young are altricial—sparsely covered with down, their eyes closed, and helpless. The fledging period is unknown, as is the post-fledging behavior of the parents. However, both parents apparently feed the young.
Le Conte’s Sparrows forage on the ground and in low, dense vegetation. Little is known of their foraging behavior. Their food is primarily grass seeds and insects.
In some areas Le Conte’s Sparrows are frequent victims of cowbird nest parasitism. Because of their preference for wet habitat, their nests are subject to occasional flooding. Historically, changes in land use practices, including the draining of swamps and bogs doubtless reduced available breeding habitat. So little is known about the natural history of the Le Conte’s Sparrow that it is difficult to assess its status, but the somewhat sparse Breeding Bird Census data suggest that most populations are stable or increasing, so this little-known sparrow may have a secure future.
William E. Davis, Jr.