Friday, May 1, 2015

Student guest post: Sedge Wren by Carley Smith

Sedge Wren (Cistothorus platensis)

Sedge Wren
Global populations of the Sedge Wren are considered secure but breeding populations in Pennsylvania are critically threatened, thus this bird is listed as an endangered species in PA. The most regular and recent sites are in Crawford and Butler county. It is seen as a very rare breeder in the PA state.

This species is a shy resident of damp meadows and grasses.  Sedge Wrens generally stay well hidden, coming into view only when singing.  Like some other Wrens, the male builds many dummy nests, only completing the one that the female selects. These dummy nests may serve as dormitories or decoys for predators. They are most commonly located in thick vegetation.They nest in June or July. Sedge wrens are characterized by high mobility during breeding season and low site tenacity between seasons. This wren prefers dense, lush and undisturbed hay fields. They are highly sensitive to habitat conditions and abandoned sites that become too dry or too wet, or where shrubs become too prevalent. Sedge wrens are secretive and unpredictable in their movements.

Similar Wren Friends
The Sedge wren is related to the Marsh Wren who normally inhabits deeper waters. Other wrens with indistinct superciliums are House, Winter and Rock Wrens. Winter Wren is more reddish-brown above, darker below and has a shorter tail. House Wren lacks white streaking on the crown and back and is less buffy on the underparts. Rock Wren is larger with a contrast between the gray back and brown rump and has buffy tips to the tail. 

The Sedge Wren is approximately 3.75 inches long with a short, thin bill. Their coloring includes brown upper parts with pale streaks on the back and crown. They have an indistinct supercilious which is a plumage feature found on the heads of some birds. However they do have buffy breast and flanks. The wings and tails of sedge wrens are barred with black.

They are Neotropical migrants, summering in the Midwest, eastern Great Plains, and south-central Canada.  Winters occurs along atlantic coast from Maryland through Florida. They can only endure short distance migrations.

They eat mostly insects and spiders. The young are fed moths, spiders, mosquitos, flies, grasshoppers, and bugs.

ADULT: Has reddish buff upperparts overall, with subtle dark barring on tail, more striking dark and pale barring on wings, bold dark and pale streaks on back, and a streaked crown; supercilium is buffy. Underparts are buffy brown overall, but palest and whitish on throat. 

JUVENILE: Similar to adult, but colors and markings are duller overall.

Sedge wren breed mostly in grasslands where they can nest low to the ground. Clutch sizes consist of 4-8 eggs. Incubation occurs for about 12-16 days and then approximately 12-14 days to fledge. They are typically colonial nesters but may also nest as lone pairs.

The biggest threat to sedge wren populations is the loss of breeding habitat due to the draining of wetlands. They have been effected by intensive mowing practices typical of modern agriculture. Sedge wrens use drier wetlands and grasslands in PA. The state has lost more than 50% of its wetlands. Those wetland types preferred by sedge wrens are the most easily drained or  otherwise modified by agriculture or developmental interests.
Previously listed as a species of special concern, the sedge wren is now considered a endangered species in New York State and Pennsylvania. Once again it is a very rare and local breeder and has experienced population declines throughout its breeding range.The best management practices for the remaining sedge wrens is the implementation of agricultural programs, such as the Conservation Reserve Enhancement Program, that idle grasslands within the state.


“Disclaimer." Sedge Wren Fact Sheet. Web. 16 Apr. 2015. <>.
“-Sedge Wren." - South Dakota Birds and Birding. Web. 16 Apr. 2015. <>.
-“Sedge Wren." , Life History, All About Birds. Web. 16 Apr. 2015. <>.
-“Sedge Wren." Sedge Wren. Web. 16 Apr. 2015. <>.
Steele, Michael A. Terrestrial Vertebrates of Pennsylvania: Baltimore, MD: Johns Hopkins UP,  2010. Print

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