Savannah Sparrow
Conservation status Least concern |

|
Scientific classification |
|
Binomial name |
Passerculus sandwichensis
(Gmelin,
1789) |
Subspecies |
see article text |
The Savannah Sparrow, Passerculus sandwichensis,
is a small
sparrow. It is the only member of the genus Passerculus
(Bonaparte, 1838).
This
passerine
bird breeds in
Alaska, Canada, northern, central and Pacific coastal USA,
Mexico and Guatemala. The Pacific and Mexican breeders are
resident, but other populations are migratory, wintering
from the southern United States to northern South America.
It is a very rare vagrant to western Europe.
Savannah Sparrow is a very variable species, with
numerous races, several of which have been split as separate
species at various times. The different forms vary
principally in the darkness of the plumage, with Alaskan and
interior races the palest, and southern Pacific coastal
forms the darkest.
This species has a typically sparrow-like dark-streaked
brown back, and whitish underparts with brown or blackish
breast and flank streaking. It has yellowish or whitish
crown and eyebrow stripes. The cheeks are brown and the
throat white.
The breeding habitat is a wide variety of open habitats
including grasslands and cultivation. Savannah Sparrows nest
on the ground, laying 3-6 eggs in a cup nest sheltered by a
clump of grass or other vegetation. They form flocks in the
winter to migrate.
These birds forage on the ground or in low bushes. They
mainly eat seeds, but insects are also eaten in the breeding
season. The song is mixture of chips and trills. The
flight call is a thin seep.
This bird was named after
Savannah, Georgia where one of the first specimens of
this bird was collected.
Although this bird is generally abundant across its
range, some coastal populations depending on salt marsh
habitat are declining.
Subspecies
Seventeen subspecies are currently recognized. One was
formerly considered a distinct species. Four additional
subspecies are not generally accepted. The subspecies are
usually divided into several groups:
- The Savannah Sparrows proper (migratory):
- P. s. labradorius, breeds in
Newfoundland, Labrador, and N Quebec
- P. s. oblitus, breeds in N
Ontario and Manitoba
- P. s. savanna (Eastern Savannah
Sparrow), breeds in the NE USA and adjacent
Canada (includes P. s. mediogriseus)
- P. s. sandwichensis (Aleutian Savannah
Sparrow), breeds on the
Aleutian Islands and W Alaskan Peninsula
- P. s. anthinus, breeds in the remainder
of Alaska, south and east to central British
Columbia and north of the Great Plains to Manitoba
- P. s. brooksi (Dwarf Savannah Sparrow),
breeds in southernmost British Columbia to
northernmost
California
- P. s. alaudinus, breeds in coastal
northern and central California
- P. s. nevadensis, breeds in the N Great
Plains and the
Great Basin
- P. s. brunnescens, breeds from central
Mexico south to Guatemala (includes P. s.
rufofuscus)
P. s. wetmorei is a doubtful subspecies which may
breed in the mountains of Guatemala. It is known from only 5
specimens, collected June 11-17, 1897, in
Huehuetenango Department.
- The
Ipswich Sparrow (formerly considered a distinct
species, some post-breeding dispersal)
- P. s. princeps, breeds almost exclusively
on
Sable Island
- The Large-billed Savannah Sparrows:
- P. s. rostratus, which breed on the Gulf
Coast of NE Baja California and NW Sonora (some
post-breeding dispersal; has distinct mtDNA genotypes)
- P. s. atratus, resident on the coast of
central
Sonora to central Sinaloa (resident)
- The Belding's Savannah Sparrows (resident):
- P. s. beldingi, resident on the Pacific
Coast from
Morro Bay, California, to El Rosario, Baja California (includes P. s.
bryanti)
- P. s. anulus, resident around
Sebastián Vizcaíno Bay, Baja California
- P. s. guttatus, resident around
San Ignacio Lagoon
- P. s. magdalenae, resident around
Magdalena Bay
- The San Benito Savannah Sparrow (resident)
- P. s. sanctorum,
Islas San Benitos
The Savannah Sparrows proper are very similar and migrant
birds can not usually be related to a breeding population
with certainty. The resident or partially migratory
subspecies are well distinguishable by size and,
particularly between groups, coloration. The Ipswich Sparrow
is somewhat larger and paler in colour 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.
References
- BirdLife International (2004).
Passerculus sandwichensis. 2006 IUCN Red List
of Threatened Species. IUCN 2006. Retrieved on 12 May 2006. Database entry
includes justification for why this species is of least
concern
- Byers, Clive; Olsson, Urban & Curson, Jon
(1995): Sparrows and Buntings: A Guide to the
Sparrows and Buntings of North America and the World.
Houghton Mifflin, Boston.
ISBN 0395738733
External link