Carolina Wren
Thryothorus ludovicianus
Summary 3
The Carolina wren (Thryothorus ludovicianus) is a common species of wren that is a resident in the eastern half of the United States of America, the extreme south of Ontario, Canada, and the extreme northeast of Mexico. Severe winters restrict the northern limits of their range while favorable weather conditions lead to a northward extension of their breeding range. Their preferred habitat is in dense cover in forests, farm edges and suburban areas. This wren is...
Summary 4
The Carolina wren (Thryothorus ludovicianus) is a common species of wren that is a resident in the eastern half of the United States of America, the extreme south of Ontario, Canada, and the extreme northeast of Mexico. Severe winters restrict the northern limits of their range while favorable weather conditions lead to a northward extension of their breeding range. Their preferred habitat is in dense cover in forests, farm edges and suburban areas. This wren is the state bird of South Carolina.
Description 5
At 12.5 to 14 cm (4.9 to 5.5 in) long, with a 29 cm (11 in) wingspan and a weight of about 18 to 23 g (0.63 to 0.81 oz), the Carolina wren is a fairly large wren; the second largest in the United States species 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). Sexual dimorphism is slight with males being larger than their mates. A study indicated that out of 42 mated pairs, all but one of male was larger than the female of the pair. The males were on average 11 percent heavier along with having longer wing chords.
There are several differences among the subspecies. For T. l. ludovicianus, the crown is rich brown that appears more chestnut-colored on its rump and uppertail-coverts. Shoulders and greater coverts are a rich brown, with a series of small white dots on the lesser primary coverts. The secondary coverts are rich brown with a darker brown barring on both webs; the bars on the primaries are on the outerwebs only, but darker and more noticeable. The rectrices are brown with 18 to 20 bars that span across the tail. The white supercilious streak borders thinly with a black above and below, and extends above and beyond its shoulders. The ear coverts are speckled gray and grayish-black. Its chin and throat are grey that becomes buff on its chest, flank and belly, though the latter two are of a warmer color. The underwing coverts sport a grayish buff color. Its iris is reddish-brown, the upper mandible is lemon-colored and paler at the base and lower mandible. The legs are flesh-colored.
As for the other subspecies in contrast to T. l. ludovicianus, T. l. berlandieri is of a slightly smaller build, but possesses a larger bill, the upperparts are duller brown with deeper colored underparts, T. l. lomitensis is of a duller color (than either ludovicianus or berlandieri) with its underparts either pale or almost white, T. l. miamensis contains darker rusty chestnut upperparts and deeper colored below. T. l. burleighi is duller and sootier with less distinct tail markings, T. l. mesophilus has paler underparts and a whiter supercilium, and T. l. tropicalis is darker than all races, and contains heavier bars than T. l. berlandieri.
The juvenile T.l. ludovicianus is similar in appearance, but the plumage is generally paler with a softer texture with buff-tipped wing coverts, a superciliary streak is less white, a fluffy vent and crissum (the undertail coverts surrounding the cloaca) without bars. In August and September, the partial plumage molt for the post-juvenile wrens is darker in color and affects the contour plumage, wing coverts, tail and develops a whiter superciliary stripe. The post-nuptial molt for adults in the same time period is more pronounced in color than the spring molt, with both sexes similar in appearance.
Survival rates differ by region. A male captured in Arkansas lived to be at least 73 months old, and in Alabama, the oldest female and male captured were six and ten years old, respectively. A mark-and-recapture analysis of the wrens analyzing survival probability within the Southeastern United States captured was monitored from 1992 to 2003. Roughly 90 percent of the banded wrens died within 10 years.
The easiest species to confuse with the Carolina wren is Bewick's wren, 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.
Habitat and distribution 5
These birds are largely resident, and will only disperse beyond their range after mild winters. Carolina wrens sporadically breed as far north as Maine and Quebec after mild winters. In certain parts of their range, such as most of Iowa, prolonged periods of snow can curtail potential expansion. Permanent breeding locations range from eastern Nebraska, southern Michigan, southeast Ontario and the New England states to Mexican states such as Coahuila, Nuevo León, San Luis Potosí and Tamaulipas and the Gulf Coast of the United States. Local occurrences with infrequent and likely breeding locations include southeast South Dakota, central Kansas, eastern Colorado, western Oklahoma and Texas as far as Maine and New Brunswick. There have been occasional vagrants spotted in Colorado, New Mexico, and Arizona, Wyoming, South Dakota, Manitoba, Nova Scotia, and the Gulf of St. Lawrence.
The range of the wrens increased northward and westward in several regions over the past few centuries. In Massachusetts, the wrens had expanded westward and northeastward from its former southeastern location in approximately 35 years, in New York the population increased three-fold in roughly 25 years, while in midwest states such as Ohio and Michigan have seen numbers of the birds increase since the mid-1800s and early 1900s, respectively. Expansion around Ontario occurred since early reports in 1890 and 1905. Explanations given include infrequent winter storms in the 20th century, expanded forest habitats, and the wrens taking advantage of urban areas containing feeders, especially in winter.
Carolina wrens adapt to various habitats. Natural habitats include various types of woodland such as oak hardwoods and mixed oak-pine woodlands, ash and elmwoods, hickory-oak woodlands with a healthy amount of tangled undergrowth. The preferred habitats are riparian forests, brushy edges, swamps, overgrown farmlands, and suburban yards with abundant thick shrubs and trees, and parks. It has an affinity for dilapidated buildings and unkempt yards in man-made areas. Subspecies burleighi and neophilus inhabit slash pine and palmettos.
Sources and Credits
- (c) Joseph F. Pescatore, some rights reserved (CC BY-ND), http://www.flickr.com/photos/jpescatore/6860147825/
- (c) Bill MacIndewar, some rights reserved (CC BY-NC), uploaded by Bill MacIndewar
- Adapted by Bill MacIndewar from a work by (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Thryothorus_ludovicianus
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Thryothorus_ludovicianus
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Carolina_wren
