Pennsylvania is home to three species of wrens that breed in the state and are considered regular parts of the avifauna. These include the House Wren, the Winter Wren, and the Carolina Wren. Two additional species, the Sedge Wren and Marsh Wren, are less common breeders that can be found in some years and specific habitats in Pennsylvania.
House Wren
The House Wren is the most widespread and commonly encountered wren in Pennsylvania. This small songbird is about 4.5 to 5.5 inches in length, with brown upperparts and lighter underparts with barring on the sides and belly. House Wrens have a long, slender bill and a short tail that is often held cocked upright.
House Wrens breed throughout Pennsylvania and are most often found in brushy, semi-open habitats with dense shrubs. They readily nest in artificial sites like nest boxes, holes in buildings, and other manmade cavities. The male House Wren builds multiple nests out of twigs and sticks and the female selects one to line with softer materials to raise the young. House Wrens are migratory and winter in the southern U.S and Mexico.
Winter Wren
The Winter Wren is a small, round-bodied wren that breeds in coniferous and mixed forests across northern and western Pennsylvania. They are dark brown overall with lighter barring on the wings, tail, and underparts. At only 3.5 to 4 inches long, the Winter Wren is even smaller than the House Wren.
Winter Wrens nest on or near the ground, using cavities in logs, roots, stumps, and other natural sites. They build a domed nest of twigs, moss, and leaves. The male Winter Wren sings a remarkably loud and complex song for such a tiny bird. Winter Wrens migrate out of Pennsylvania for the winter, traveling to the southeastern U.S. and farther south.
Carolina Wren
The largest wren in Pennsylvania, the Carolina Wren reaches lengths of 5.5 to 6.5 inches. Their plumage is warm rufous-brown above and lighter brown to tawny on the underparts with white throat streaking. The long bill is slightly decurved.
Carolina Wrens breed across southern Pennsylvania and their range has expanded northward in recent decades. They prefer brushy habitat near woodland edges and are common in suburban parks and backyards. Carolina Wrens will readily use nest boxes but also nest in natural and manmade cavities. They build bulky nests out of bark, leaves, sticks, and feathers. Some Carolina Wrens may be permanent residents in Pennsylvania, while others withdraw south or perish when severe winters hit the state.
Sedge Wren
The Sedge Wren is an inconspicuous species that inhabits wet meadows, marshes, and grassy swamps. They are quite variable in color but generally show fine streaking on their back and crown and have light underparts with fine barring. Their bill is shorter and more slender than other wrens.
Sedge Wrens are uncommon and localized nesters in Pennsylvania. They can be found in scattered wetland habitats, mainly in the western part of the state. Males build several nests of grasses near the ground, and the female selects one to line with feathers to raise the brood. Sedge Wrens winter along the Gulf Coast and farther south to Panama.
Marsh Wren
Similar in size and shape to the Sedge Wren, the Marsh Wren also breeds in wetland habitats in Pennsylvania, primarily in the marshes of the Erie National Wildlife Refuge in the northwest corner of the state. Marsh Wrens are rich brown above with a light eyebrow stripe. The back is streaked with black and white.
Marsh Wrens eat insects and build domed nests attached to reeds and grasses over water. The male constructs multiple nests, and the female lines one with feathers and lays eggs. Marsh Wrens are quite secretive in their wetland habitat. They migrate from Pennsylvania in fall to the southern coastal states and Mexico.
When and Where to See Wrens in Pennsylvania
The breeding season is the best time to find wrens in Pennsylvania. House Wrens, Winter Wrens, and Carolina Wrens all nest in the state during the spring and summer months. Sedge Wrens and Marsh Wrens are also summer residents but more localized and uncommon. Here is a summary of when each species breeds in Pennsylvania:
Species | Breeding Season |
House Wren | May to August |
Winter Wren | May to July |
Carolina Wren | March to August |
Sedge Wren | May to August |
Marsh Wren | May to August |
In winter, only the Carolina Wren regularly stays in Pennsylvania though a few Winter Wrens and House Wrens may overwinter in some years. Winter is the best time to find Carolina Wrens at feeders.
The specific locations to find breeding wrens in Pennsylvania include:
- House Wrens – Open woodlands, forest edges, parks, backyards. Statewide.
- Winter Wrens – Coniferous and mixed forests. Northern and western PA.
- Carolina Wrens – Brushy habitat near woodlands. Southeastern PA.
- Sedge Wrens – Marshes, wet meadows. Scattered sites in western PA.
- Marsh Wrens – Marshes at Erie NWR.
Wren Nests and Behavior
One of the most interesting aspects of wrens is their elaborate and decorative nests. While wren species utilize cavities for their nest sites, they fill these spaces with intricately built nests.
Male House Wrens and Winter Wrens construct multiple nests out of twigs and sticks. The females then select one nest to line with softer materials. House Wrens use feathers, grasses, weed stalks, and even casts of insects to line their nests. Winter Wren nests are decorated with moss, leaves, bark strips, spider egg cases, and feathers on the inside.
Marsh Wrens weave domed nests out of reeds and grasses, often with side entrances. Carolina Wrens build bulky nests filling a cavity with twigs, leaves, bark strips, and other debris.
Wrens are energetic and inquisitive birds, almost always in motion as they flit through vegetation looking for insects. Their small size belies the loud voices of wrens. Males sing boisterous and complex songs to defend territories and attract mates. The Carolina Wren’s voice is ringing and upbeat, while the Winter Wren has one of the loudest songs relative to its size.
Wrens often hold their short tails cocked upright. They have a strong drive to build their elaborate nests. If a nest is disturbed or destroyed during nest building, the male will frequently build a new replacement nest nearby. Wrens raise one to two broods per breeding season.
Threats to Wrens
Wren populations face a variety of threats throughout their ranges. As small songbirds, wrens are vulnerable to predation from birds of prey, snakes, squirrels, raccoons, cats, and other predators. House Wrens and Carolina Wrens benefit from nest boxes and other manmade nest sites to help boost productivity.
Habitat loss is always a concern, as wrens rely on specific vegetation and nest sites. Marsh Wrens are especially impacted by wetland drainage and destruction. Sedge Wrens have declined along with the availability of grassy wet meadow habitat.
Climate change may affect the seasonal timing and migration patterns for species like Winter Wrens and Sedge Wrens. Severe winter weather and storms can take a toll on wintering wrens. The use of pesticides reduces insect prey availability.
Collisions with buildings, cars, and towers while migrating also contribute to wren mortality. Public education on keeping cats indoors, installing nest boxes, and protecting wetland habitat can help conserve wren populations.
Attracting Wrens to Your Yard
Wrens make lively additions to backyards and gardens during the breeding season. You can encourage wrens to take up residence by following some of these tips:
- Install nest boxes suited for wrens at least 5-6 feet off the ground.
- Plant dense shrubs and bushes that offer cover and roosting spots.
- Reduce use of pesticides so insects are available as food.
- Provide a brush pile as a potential nest site.
- Offer a shallow bird bath for drinking and bathing.
- Put out suet feeders to provide high calorie food.
Making your yard inviting to nesting wrens allows you to observe their behavior up close. Watching the male dart about with nesting material, listening to his vibrant songs, and seeing the chicks fledge is a rewarding experience.
Conclusion
Wrens hold a special place among Pennsylvania’s avifauna. Their energetic personalities, complex songs, and elaborate nests make them fascinating birds to study and observe. Pennsylvania is home to five types of breeding wrens including familiar backyard birds like the House Wren and Carolina Wren.
Getting to know the habitat preferences, nesting behavior, migration patterns, and conservation issues for Pennsylvania’s wrens gives bird enthusiasts a better appreciation of these small songbirds. Attracting wrens to backyards and wetlands provides an opportunity to support their populations through firsthand observation and habitat management.