By Peter Vankevich
The Savannah Sparrow (Passerculus sandwichensis) is one of the most common sparrows throughout much of North America, but on Ocracoke, it is only a fall and winter visitor as it is for much of North Carolina.
This bird breeds from the far north throughout Alaska and most of Canada, down into the United States in the West to southern California and northern New Mexico, across to the Great Lakes region, and the southern Appalachian mountains. There is also a population in Baja California and Central Mexico.
In North Carolina it is presumed to nest in the upper northwest of Ashe, Sparta and Wilkes counties since adults have been seen carrying food, though finding an active nest has yet to be accomplished, according to Carolina Bird Club’s listing of the birds of North Carolina and their distribution and abundance. The state is well within its wintering area from the southern United States across Central America and the Caribbean to northern South America.
Despite its mixed woodland-grassland habitat name, it was actually named for the city of Savannah, Georgia, by ornithologist Alexander Wilson where he discovered it in 1811.
The name is, nevertheless, somewhat fitting. Their habitats are grasslands with few trees, meadows, pastures, grassy roadsides, sedge wetlands and cultivated fields planted with cover crops like alfalfa. In Alaska and northern Canada, they live among the shrubby willows of the tundra. Along the coast, they also inhabit tidal salt marshes, estuaries and sand dunes.
A handsome sparrow, its appearance is somewhat variable throughout its extensive range. The number of subspecies is debatable, but currently about 17 are recognized, including the Ipswich, which will be discussed below. Plumage consists of a mottled brown back and dark streaks on its white breast. A yellowish or pale eyebrow stripe, called a lore, can sometimes be seen. Both male and females look alike, i.e., they are sexually monomorphic in plumage. It also has a short-notched tail.
On Ocracoke, Savannah Sparrows may be confused with the year-round Song Sparrow, which has a grayish or pale eyebrow on a streaked chest with a spot in the center and two brown cheek stripes, a whitish throat, and a long tail. Note that some Savannah Sparrows may also have a center spot on the breast.
Despite the ability to migrate thousands of miles, Savannah Sparrow are primarily ground birds. The nest, built only by the female, is made of dry grasses, is usually embedded on the ground in thick vegetation. They forage primarily by walking, feeding on seeds as well as insects and spiders. Like many herbivorous birds, they will eat more insects during breeding season. Those in coastal habitats will also consume small mollusks.
The clutch size is between two and six eggs, commonly four. Only the female incubates and both parents bring food to the nest. The first chicks hatch 14 to 16 days after first egg is laid and leave the next in about 10 days. The fledglings reach independence after two or three weeks.
After fledging, a second clutch may be laid. A threat to a successful fledge are Brown-headed Cowbirds which will lay eggs in the sparrows’ nests where the two species co-occur.
When flushed, they usually fly a short distance and perch in a bush or dive into the grasses.
The Ipswich Sparrow and Sable Island
One cannot write about Ocracoke’s Savannah Sparrows without mentioning the Ipswich Sparrow ( (Passerculus sandwichensis princeps) and its unique summer home.
Considered a subspecies, it can be found on Ocracoke along with the other eastern Savannah Sparrows.
The Ipswich is larger and paler in color than other eastern Savannah sparrows and the breast streaks are narrower and pale brown.
It winters along the dunes and beaches from Nova Scotia to Georgia.
The nesting grounds for the Ipswich is a narrow 25-mile long and less than one mile-wide, crescent-shaped sandbar known as Sable Island (sable is sand in French) located more than 100 miles off the coast of Nova Scotia . Uninhabited with the exception of a few Parks Canada staffers and some seasonal researchers, this island is home to about 500 horses and the largest breeding colony of grey seals in the world. A separate profile on this fascinating sparrow will follow.
Best time to see: October into late March, not present in summer
Where: Throughout the island, except for the village, and especially in the dunes and adjacent grasses. If you see a sparrow on the beach from fall into early spring, it is likely to be a Savannah Sparrow.
(Audio provided courtesy of OhioLINK Digital Resource Commons)