When I was learning to identify birds, I spent hours puzzling over sparrows that, in retrospect, were probably all of the same species. It was frustrating, but later I turned the experience into ID advice. If you see a compact, streaky sparrow in an open habitat, start by asking yourself: Is this a Savannah Sparrow?
Often, the answer will be: Yes. The Savannah Sparrow is one of the most widespread native sparrows in North America. Its breeding range extends from the shores of the Arctic Ocean in northern Alaska and Canada south to highlands of southern Mexico, with an isolated population in high mountains of Guatemala. In winter, it leaves northern areas, but it still can be found coast to coast in the southern United States, with a few north to the Great Lakes and coastal regions of southern Canada. In migration, it might be seen practically anywhere on the continent.
This bird has a broad range partly because it’s adapted to a wide variety of open habitats with low vegetation. It may be found nesting in native grassland, farm fields, pastures, tundra, or salt marshes. In winter, it abandons the tundra but still abounds in the other habitats, as well as other open areas such as golf courses and among the dune grass on beaches.
Outside the breeding season, Savannah Sparrows form small, loose flocks, usually of fewer than 20 birds, although they may gather in larger flocks in late summer. Unlike many sparrows of grasslands or marshes, they’re not especially shy. Some sparrows found in similar habitats (like Baird’s, Henslow’s, Nelson’s, or LeConte’s Sparrows) can be solitary skulkers, very hard to glimpse, but little groups of Savannah Sparrows may forage on open ground or perch up on fence wires where they’re easy to see.
Savannah Sparrows have few obvious field marks, and in overall pattern, they are similar to Song Sparrows, which are also very widespread (and variable). Some Savannahs are readily distinguished by bright yellow above the lores, but this can be faint or absent, so shape and behavior are more consistent clues. In flight, Savannahs look relatively buoyant, flitting lightly above the ground; most other small grassland sparrows tend to look heavier and more labored in flight, flapping furiously to stay airborne. Among open-country sparrows, the Vesper Sparrow is the one that behaves most like the Savannah, but it has some clear differences in pattern.
Individual variation in color occurs throughout the range of the Savannah Sparrow, but there are also striking regional variations along the edges of the continent. The “Ipswich” form is a sought-after specialty of Atlantic Coast beaches in winter. “Belding’s” Savannah Sparrow is limited to salt marshes of southern California and Baja. The “Large-billed” form, likely to be considered a full species in the future, appears in southern California as a post-breeding visitor from Mexico. All three of these distinctive sparrows are shown in Brian Small’s photos in this column.
Key field marks
- Narrow white or gray central stripe between dark crown stripes
- Variable wash of yellow above lores, sometimes absent
- Fine streaks on chest and down onto flanks
- Pink legs sometimes noticeable
- Wings relatively plain, with no wing bars
- Compact shape emphasized by medium-short tail, notched at tip
What to look for
Size and shape. A small sparrow with a medium-short tail and (in most regions) a small bill.
Habitat and behavior. Very open situations: grassland, farm fields, marshes, beach grass in coastal dunes, tundra (summer). Often in small flocks, not shy or hard to see.
Crown pattern. Dark crown, usually divided by narrow white median stripe (dull or missing in some regions).
Face pattern. Well-defined dark eye line, dark lower edge of ear coverts, narrow dark moustache mark. Often but not always has yellow above lores.
Underparts. Fine streaking on chest and extending down flanks, with much geographic variation in darkness of streaks.
Some elements of face pattern are seen in many sparrows (and many other species) because they define the edges of particular tracts of feathers that are arranged in the same way on most birds. The Savannah Sparrow has all these generic marks, including a pale eyebrow and malar stripe, dark stripes on the side of the crown, and dark lines behind the eye, along the lower edge of the ear coverts, and at the sides of the throat. Most sparrows have at least some of these marks, and some species, like Song Sparrow, show all of them. To be confident in identifying the Savannah Sparrow, focus on learning its shape, behavior, overall pattern, and variations in color.
In plumage pattern, the bird most similar to Savannah Sparrow is another very widespread and variable species, Song Sparrow. It lacks the yellow above the lores shown by many Savannahs, and its median crown stripe is often duller; but most markings of the two species are similar and equally variable in both. Song Sparrows are best identified by their different shape and behavior. They’re distinctly longer-tailed, larger-headed, stout-bodied birds, usually found in thickets and other heavy vegetation (although they occur with Savannah Sparrows in some marshes). If disturbed, they dive into dense cover, giving a loud chiff callnote. Savannah Sparrows are more likely to perch in an open spot, and their calls are light, lisping sounds.
The amount of yellow above the lores on Savannah Sparrows is variable. It can be obvious, limited (as on the bird in this photo), or missing altogether. Another irregular mark involves the outer tail feathers. They are often paler than the rest of the tail, and in some they are conspicuously white. That can lead to some confusion because Vesper Sparrows — often found in the same habitat as Savannahs — are known for their contrasting white outer tail feathers. However, the Vesper Sparrow is a larger, longer-tailed bird. Its face pattern is noticeably different, with fine streaks on the crown, a white eye-ring, and a bold dark outline on the lower edge of the ear coverts.
In salt marshes of the southern California coast, north to Santa Barbara County, “Belding’s” Savannah Sparrow is a permanent resident. It’s a small and dark form, with blackish streaking on the underparts, often most noticeable where the wide dusky stripes extend down onto the flanks. Genetic studies suggest that the subspecies beldingi, along with three other races found farther south in Baja, might represent a distinct species. However, a very similar subspecies (alaudinus) occurs just north of beldingi and along most of the rest of the California coast. Genetically, it may be closer to typical Savannah Sparrow, but it may interbreed with the Belding’s form where their ranges meet, so the situation is still uncertain.
This distinctively drab bird has an unusual distribution: It breeds only in Mexico, in marshes around the northern and eastern edge of the Gulf of California, and it enters the United States only as a post-breeding visitor. From early fall through early spring, small numbers can be found along the southern California coast (rarely north as far as Point Reyes) and in the interior around the edges of the Salton Sea. It looks much paler than other Savannah Sparrow populations found in the same areas, with much less contrast on the back and crown, and its bill is noticeably larger. There’s a good chance this form will be treated as a distinct species, Large-billed Sparrow, in the future.
Across the continent from the Large-billed form, another pale bird, the “Ipswich” Savannah Sparrow, has an even more limited range. It nests only on Sable Island, about 100 miles off the coast of Nova Scotia, and rarely on the nearest mainland. Its winter range extends along Atlantic Coast beaches south to the Carolinas, mostly in the grass among the dunes. One of the largest and thickest-billed forms in the Savannah Sparrow complex, it’s recognized by its winter habitat and by its beautiful combination of pale gray and pale reddish-brown markings. Although the “Ipswich” is sometimes considered a full species, it readily interbreeds with typical Savannahs that wander to Sable Island, and genetic studies suggest that it’s not specifically distinct.
What’s in a name?
Savanna, an open grassland with scattered trees, is one habitat used by the Savannah Sparrow. But that’s a coincidence. In 1811, Alexander Wilson named the species for Savannah, Georgia, where he had found it for the first time.
Wilson wrote two accounts of this bird. In Volume 3 of American Ornithology, he called it Savannah Sparrow, while in Volume 4 he called it Savannah Finch. Both times, he used the scientific name Fringilla savanna. Today it’s known by the scientific name Passerculus sandwichensis. Why the change?
The genus name, Passerculus, was coined by C. L. Bonaparte in 1838. It’s not unusual for a species to be moved from one genus to another. But what about that specific name, sandwichensis? After all, the bird isn’t found in Hawaii (aka the Sandwich Islands) — nor near Sandwich, England, for which the Sandwich Tern is named.
As it turns out, before Alexander Wilson named the species in 1811, it had been described to science already by German biologist J. F. Gmelin as Emberiza sandwichensis in 1789. Gmelin’s description was a second-hand account of specimens collected at a place then called “Sandwich Sound” in Alaska. Wilson didn’t notice that his Georgia specimens matched the description of the Alaska bird. By the rules of scientific nomenclature, Gmelin’s name for the species has priority. But in English, we still use the name proposed by Wilson.
This article was first published in the January/February 2022 issue of BirdWatching Magazine.