Troglodytes pacificus (Pacific Wren) and Troglodytes hiemalis (Winter Wren)
Length: 4 inches
Wingspan: 6 inches
Seasonality: Migrant / Winter
ID Keys: Very small, dark brown overall, heavy dark barring on
flanks, short tail.
Prior
to 2010, "Troglodytes troglodytes", the "Winter Wren", was considered one
species. However, research revealed a genetic split between the wrens
found in the western North America, eastern North America, and Eurasia.
They were split into three distinct species in 2010, with the two North American
populations named Pacific Wren and Winter Wren. The Pacific Wren is found
in the humid forests of the Pacific Northwest, while the Winter Wren is found in
eastern North America. Research indicates a genetic split between the two
species going back at least 4 million years, and evidently the two populations
do not commonly interbreed. They are distinctly separated by geography,
and South Dakota is one area where both the Pacific and Winter Wrens may be
seen, with Pacific Wrens likely found in the Black Hills, while those birds
found in the eastern part of the state are likely Winter Wrens.
Both birds are fond of dense forest undergrowth, often staying out of sight as they
forage along the ground through thickets and fallen logs. While often
difficult to spot, during breeding season the males will sometimes flit up to
higher perches to sing extremely long complex songs, lasting 6-8 seconds or more
and consisting of over a hundred separate notes. In addition to genetic
differences and differences in range, the males' songs also are distinctly
different between the two populations. Note the photo to the right is
of a Pacific Wren, taken along the Oregon Coast, while the photo found below
is of a Winter Wren. All of the "additional photos" found at the
bottom of the page are of Pacific Wrens.
Habitat
During the summer breeding season, they are primarily found in moist conifer forests with a dense understory, often near water. They winter in similar forest habitats with dense understories, although they will use deciduous and mixed forests as well as conifer forests.
Diet
Primarily feeds on insects and spiders, as well as snails, millipedes, tiny fish, and berries.
Behavior
Often forages low in dense thickets and undergrowth, in vegetation and also along the ground. They may also occasionally forage along streams and pick items from the water's surface. Unlike some other wren species, both Pacific and Winter Wrens tend to utilize heavy cover even when males are furiously singing their territorial songs. The birds are often much easier to hear than see.
Breeding
Non-breeder in South Dakota
Song
A very high-pitched notes with rapid trilling interspersed. Click here to listen to the Winter Wren's song . Click here for the Winter Wren's call .
Migration
Even prior to the species split into Pacific and Winter Wrens, major differences were found between migration patterns in western and eastern birds. Pacific Wrens are primarily permanent residents along much of the Pacific Coast, all the way up to through the southern coast of Alaska, although some movements to lower elevations may occur in the fall. Winter Wrens summer in the southern half of Canada, the Great Lakes region, and New England, while wintering in the eastern U.S. as far north as Illinois, Ohio, and New York and southward to the Gulf Coast. Some Winter Wrens are also evidently permanent residents in parts of the Appalachians.
Interactive eBird Maps: Click here to access an interactive eBird map for Pacific Wren sightings . Click here to access an interactive eBird map for Winter Wren sightings.
Similar Species
House Wren
Conservation Status
Numbers appear to be stable.
Bottom Photo (Winter Wren) - Out-of-state photo, Courtesy of Norman Smith .
