The Savannah sparrow (Passerculus sandwichensis) is a small New World sparrow that is the only member of the genus Passerculus. It is a widespread and abundant species that occupies open grassland habitats in North America. Over most of its range it is migratory, breeding in Canada and the northern United States while wintering in Mexico and the southern United States. It is a sexually monomorphic species that is quite variable in appearance. Around 17 subspecies are currently recognised. These are divided into several groups, some of which have sometimes been considered as separate species. The species name sandwichensis is Latin from Sandwich Sound (now Prince William Sound) in southern Alaska from where the first specimen was collected. The common name refers to Savannah, Georgia, where Alexander Wilson observed the species in 1811.
Taxonomy The Savannah sparrow was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the buntings in the genus Emberiza and coined the binomial name Emberiza sandwichensis. Gmelin based his text on the Sandwich bunting that had been described by John Latham in 1783 and the "Unalasha bunting" that had been described by Thomas Pennant in 1785. Latham and Pennant had access to a specimen owned by the naturalist Joseph Banks that had been collected in May 1778 from Sandwich Sound (now Prince William Sound) in southern Alaska during James Cook's third voyage to the Pacific Ocean. The specimen has not survived, but a coloured drawing of the bird made during the voyage by the artist and naturalist William Ellis is now held by the Natural History Museum in London. The Savannah sparrow is now the only species placed in the genus Passerculus that was introduced in 1838 by the French naturalist Charles Bonaparte. The English name "Savannah sparrow" was introduced in 1811 by the Scottish-American ornithologist Alexander Wilson in the third volume of his American Ornithology; or, the Natural History of the Birds of the United States. Wilson had first seen the species on the coast near Savannah, Georgia. A 2005 study that compared mitochondrial DNA sequence found that the Ipswich sparrow, formerly usually considered a valid species (as Passerculus princeps), was a well-marked subspecies, whereas the southwestern large-billed sparrow was more distinct (Passerculus rostratus). Seventeen subspecies (including the large-billed sparrows) are currently recognized, though many are only described from wintering birds and much of the variation seems to be clinal. Four additional subspecies are no longer generally accepted. The complex is usually divided into several groups:
Savannah sparrows proper
All are migratory; wintering ranges overlap widely.
P. s. labradorius Howe, 1901 – breeds in Newfoundland, Labrador, and N Quebec. Includes P. s. oblitus. P. s. savanna (Wilson, A, 1811) – (eastern Savannah sparrow), breeds in the northeast US and adjacent Canada (includes P. s. mediogriseus) P. s. sandwichensis (Gmelin, JF, 1789) – (Aleutian Savannah sparrow), breeds on the Aleutian Islands and west Alaskan Peninsula P. s. anthinus Bonaparte, 1853 – breeds in the remainder of Alaska, south and east to central British Columbia and north of the Great Plains to Manitoba. Includes P. s. crassus. P. s. brooksi Bishop, 1915 – (dwarf Savannah sparrow), breeds in southernmost British Columbia to northernmost California P. s. alaudinus Bonaparte, 1853 – breeds in coastal northern and central California P. s. nevadensis Grinnell, 1910 – breeds in the northern Great Plains and the Great Basin P. s. brunnescens (Butler, AW, 1888) – breeds from central Mexico south to Guatemala (includes P. s. rufofuscus) P. s. wetmorei Van Rossem, 1938 – a doubtful subspecies that may breed in the mountains of Guatemala. It is known from only five specimens, collected June 11–17, 1897, in Huehuetenango Department.
Ipswich sparrow Some post-breeding dispersal. Formerly considered as a distinct species.
P. s. princeps Maynard, 1872 – breeds almost exclusively on Sable Island which lies southeast of Nova Scotia in the North Atlantic Ocean. The Ipswich sparrow is somewhat larger and paler in color than other eastern Savannah sparrows. The breast streaks are narrower and pale brown. Some birds overwinter on the island; others migrate south along the Atlantic coast, usually departing later and returning sooner than mainland birds. Some birds interbreed with P. s. savanna in Nova Scotia. These birds frequently raise three broods in a year. This bird was first observed in winter on the dunes near the town of Ipswich, Massachusetts.
Large-billed sparrows The large-billed sparrows proper is sometimes treated as a separate species. There are two dark, large and strong-billed subspecies:
P. s. rostratus (Cassin, 1852) – breeds on the Gulf Coast of northeast Baja California and northwest Sonora (some post-breeding dispersal). P. s. atratus Van Rossem, 1930 – resident on the coast of central Sonora to central Sinaloa (resident) Belding's (Savannah/large-billed) sparrows are all-year residents of salt marshes of the Californian Pacific coast. They are dark, rufous, and have rather long but not very hefty bills. This group has been considered as a separate species.
P. s. beldingi Ridgway, 1885 – resident on the Pacific coast from Morro Bay, California, to El Rosario, Baja California (includes P. r./s. bryanti) P. s. anulus Huey, 1930 – resident around Sebastián Vizcaíno Bay, Baja California P. s. guttatus Lawrence, 1867 – resident around San Ignacio Lagoon P. s. magdalenae Van Rossem, 1947 – resident around Magdalena Bay San Benito (Savannah/large-billed) sparrow is a resident bird of the Islas San Benito off Baja California; a stray bird was observed on Cedros Island on April 21, 1906. It has been considered as a separate species.
… excerpt ends here. Continue reading the full article.
