The Carolina Wren (Thryothorus
ludovicianus) is a common species of wren, resident in the eastern
half of the USA, the extreme south of Ontario, Canada, and the extreme
northeast of Mexico. Thryothorus ludovicianus is the state bird of South
Carolina; its specific name ludovicianus means "from Louisiana".
Typically 12.5 to 14 cm (4.9 to 5.5 in) with a 29 cm (11 in) wingspan
and a weight of about 18 to 23 g (0.63 to 0.81 oz), it is a fairly
large wren; among the United States species it is second largest
after the Cactus Wren. Among standard measurements, the wing chord
is 5.4 to 6.4 cm (2.1 to 2.5 in), the tail is 4.5 to 5.6 cm (1.8
to 2.2 in), the culmen is 1.4 to 1.8 cm (0.55 to 0.71 in) and the
tarsus is 2 to 2.3 cm (0.79 to 0.91 in). The upperparts are rufous
brown, and the underparts a strong orange-buff, usually unmarked
but faintly barred on the flanks in the southwest of the range. The
head has a striking pure white supercilium (eyebrow) and a whitish
throat. The race albinucha is duller brown above and has additional
white streaking on the head.
It is easiest to confuse with the Bewick's Wren, a fairly close relative,
which differs in being smaller but with a longer tail, grayer-brown
above and whiter below. The Carolina and White-browed Wrens differ
from the House Wren in being larger, with a decidedly longer bill
and hind toe; their culmen has a notch behind the tip.
The Carolina Wren is noted for its loud song, popularly rendered
This song is rather atypical among wrens. A given bird will typically sing several
different songs. Only the male birds sing their loud song. The songs vary
regionally, with birds in northern areas singing more slowly than those in southern
The Carolina Wren also has a series of calls, including a rapid series of descending
notes in a similar timbre to its song, functioning as an alarm call, and a very
harsh and loud scolding call made to threaten intruders.