Bird Highlights 2, Wrens
Wrens: Family Troglodytidae
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| Adult Carolina Wren near nest site |
The Wren family is a group of small or midsized passerines that occur mostly in the Americas although one species or group is cosmopolitan (present in most parts of the world). These birds are familiar to many people as small, nondescript birds that move like a mouse in coppices or brambles, or take up residence in mailboxes or flowerpots. In Europe, the Winter Wren or Eurasian Wren is simply referred to as Wren and is the stereotypical bird in this group, while in North America we have a total of nine species of wren. While the birds themselves are not that attractive with a few notable exceptions, wrens have some of the most beautiful songs and are quite loud for their size. In the Carolinas, we have five species of wren with all of them occurring in the Cape Fear and Grand Strand Region at some point in the year. As with Parulidae Wood Warblers, Old World Warblers, and other birds, there are wrens for almost every habitat with some birds being specialists.
Brief Ecology: Wrens are generally insectivorous songbirds that live on or near the ground where they can be difficult to see. Aside from their secretive habits and some behavior differences, wrens are not that different from other songbirds. In our area, there are wrens in virtually any habitat from saltmarsh to high-elevation forests. Three wren species which will be described later are generalists that occupy a wide range of habitats, while two species are specialists found mostly in wetlands. Most wrens are short-distance migrants or nonmigratory altogether and generally fly short distances and maintain territories throughout the year.
Wren Species
Of the five species of wrens that live in our area, three of them are likely to visit or reside in our gardens, while the other two are dependent on wetlands or marshes. All wrens are common in our area and occur in good numbers within the right habitat and season. The first group of wrens will be referred to as the Woodland Group, while the second group are the species that occupy wetlands.
Wood Wrens
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| A Carolina Wren, notice the yellowish undersides and white eyeline Curtis Downey, circa 2018 |
Carolina Wren Thryothorus ludovicianus: The Carolina Wren is the default wren in our area and is the one we are most likely to encounter. This bird is also the largest wren in our area at 15-17cm (6-7") long or about the size of a House Sparrow. Its reddish-brown back, orange or yellow undersides and fairly long bill is distinctive. While it is still a small bird and can be hard to see, Carolina Wrens are conspicuous and loud and often come out into the open to sing from posts or treetops. This bird also sings year-round and has a loud chanting song that sounds like "Teacher Teacher Teacher" as well as loud ratcheting sounds that are comparable to a turning crank or noisemaker (listen to song through the Cornell Link). This wren is found in almost any wooded habitat from forest interiors to hedgerows. They are common in wooded gardens, parks, and near older homes or masonry structures. This species does not migrate and breeds from March to August, raising 2-3 broods per year. This wren may come to bird tables for mealworms, dried fruits, peanuts, sunflower seeds, and suet. Carolina Wren Profile, Cornell Lab.
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| House Wren in garden, this bird is usually found below waist level Curtis Downey, circa 2012 |
House Wren Troglodyte aedon: The House Wren is a common and more "stereotypical" wren that is common across North America but is seen in our area mainly as a spring or autumn migrant. This bird is much smaller (10cm or 4" ) and is tan brown or greyish in coloration. Like its larger relative, it has a fairly long bill, long tail, and has very loud song. This wren's song is more like a descending trill or twittering song (song can be found on Cornell Profile). In its breeding range, House Wrens often nest near human habitation and will use birdhouses, gourds, or manmade objects readily. In our area this bird is secretive and difficult to spot. Look for them in ankle to waist high thickets, weeds, or around masonry or debris from August to November. House Wren Profile, Cornell Labs
 Winter Wrens are darker than House Wrens |
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Winter Wren Troglodyte troglodyte (or hiemalis): The Winter Wren is the smallest and least common of the "Wood Wrens" and as its name implies it is mostly seen during the winter. This is also the species that occurs in Eurasia although scientists have recently split this group into three separate species. This bird is tiny like the House Wren except with a shorter tail and beak. It is about 8-10cm or 3-4 inches long, which is shorter than our Ruby Throated Hummingbird making it one of our smallest birds, besides the Golden Crowned Kinglet. Adults can be dark brown or sooty grey in coloration. This bird nests in the Appalachian Mountains and is common around Mount Mitchell State Park where its ethereal song can be heard from meadows or woodland edges (song recording on Cornell Profile). They occur in our area from late October to March and are generally quiet, elusive, and difficult to find. This wren is mostly found in woodlands, and swamps although it can be found in almost any habitat including coastal jetties. In gardens where it remains in brambles, shrubs, or amongst rocks but may forage along home foundations. They may feed under bird tables or sample suet and may follow chickadee or titmouse flocks. Winter Wren Profile, Cornell Lab
Marsh Wrens
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| Credit: Wikimedia Foundation (Creative Commons) Creative Commons License page |
Marsh Wren Cistothrous palustris: The Marsh Wren is a bird that lives in extensive marshes and is found throughout the year in the Carolinas. They are about the same size the House Wren but share the brighter colors of the Carolina Wren. They nest in colonies in cattails, Phragmites, or Spartina Grass and only visit gardens rarely if they are next to marshes. Its song is similar to a blackbird call and is difficult to hear. Marsh Wren Profile, Cornell Lab
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| Credit: Wikimedia Foundation (Creative Commons) Creative Commons License Page |
Sedge Wren Cistothrous platensis: The Sedge Wren is a fairly uncommon but likely underreported species that can be seen from October to March though it could be present at any time. This bird is small like the House or Winter Wren and can easily mistaken for either species. Up close this wren has a mottled pattern and slightly hooked bill. They nest in meadows and marshes and can be found in any grassy or damp habitat during migration including roadside ditches or sometimes gardens. Sedge Wren Profile, Cornell Labs
In the Garden
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| Wren fledglings circa 2013 |
While identifying wrens (and other little brown birds) can be difficult, we are fortunate that there are only three species that are commonly occur in gardens. The two "Marsh Wrens" often require a trek into the marsh and a good ear or eye to find. Carolina, House, and Winter Wrens are all fairly easy to attract to the garden as they like wooded, brushy, or landscaped areas, and often shelter, feed, or nest in masonry, buildings, or manmade objects.
Traits: Wrens are most likely to be found in hedges, brambles, rose thickets, or wooded borders within or along the edges of neighborhoods, parks, and even certain urban habitats (dooryards and such). The mostly feed on or near the ground on insects, snails, and move through vegetation or debris like a mouse. With the exception of the Carolina Wren, these birds rarely come out into the open and are likely to be missed unless they are singing or you happen upon a nest. During the autumn and winter months, House and Winter Wrens are quiet and difficult to find even when the leaves and herbaceous vegetation dies back. Places to look for wrens include brush piles, stonewalls or masonry structures, garden sheds, uprooted trees, logs, as well as in flowerbeds and vegetable gardens. During cold winter nights, Carolina and Winter Wrens may shelter in birdhouses, under eaves, near outdoor lights, or in outbuildings. Filling boxes with pinestraw, putting out wicker baskets, and gourds can create shelter for these birds.
Garden Notes: Wrens are good helpers in the garden as they eat garden pests including caterpillars, snail/slugs, and plant eating beetles. The Carolina Wren may nest up to three times in a season and each nest requires thousands of insects and snails. Because of their fast and agile traits, wrens are seldom prey upon by predators although cats, snakes, and weasels may get their nests, and a skilled sparrowhawk (specifically the Sharp Shinned Hawk) could catch an adult. Wrens often follow gardeners as they dig or go about their business, while nests may be found in old watering cans, boots, window screens, and even within ivy or Virginia Creeper on a wall. With the exception of birds nesting in inconvenient spots or occasionally entering homes or garages, wrens rarely cause problems in the garden.
Nesting: Carolina Wrens have a long breeding season that can extend from March to August and along with cardinals, mockingbirds, and robins they may nest two or three times during a season. The same is true for for the House Wren although it generally arrives on its nesting grounds in Mid-April. Carolina Wrens will nest almost anywhere that is protective and constructs a complex domed nest of pine straw, roots, grass, moss, and other materials that looks like a globe. The Winter Wren builds a similar nest that is a little smaller. House Wrens nest in woodpecker holes, tree hollows, birdhouses, or manmade objects and make a pile of twigs. Carolina Wrens typically build multiple nests sites and choose on or two for nesting, although unused sites may be used for roosting as well. They lay 3-6 eggs that are incubated for 12-14 days, while the young leave the nest after another 14 days. This species is quite secretive and most nests will not be noticed until the young hatch or they are happened upon. The incubating female also leaves the nest only occasionally.
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| Wicker finch basket with wren nest |
Nest Sites: Carolina Wrens rarely use birdhouses for nesting. Instead they normally nest in brambles, vine tangles, tree holes, and natural crevices. These birds will also nest on the ground, in rodent burrows, Spanish Moss, or in old bird nests or squirrel dreys. Their nests can turn up in manmade objects such as watering cans, old boots, cardboard boxes, hanging planters, mailboxes, or outdoor light fixtures as well as between window screens, dryer vents, or under overhangs. Carolina Wrens will nest in gourds, wicker baskets, open-sided nest boxes, or on shelves placed on buildings or in wooded areas.
Feeder Tips: Carolina Wrens are the only members of the family that readily come to bird tables and most birds will become reliable visitors once they find it. They prefer suet, lard, mealworms, fruits, and peanuts but will also take sunflower seeds, safflower, table scraps, and anything else you put out. Resident pairs often bring their young to feeders and offspring from earlier broods while neighboring pairs will gather during the late summer into autumn. Wrens will use any kind of feeder and often come to window feeders, open topped bird tables, tube feeders and suet cages. The House Wren rarely visits bird tables but may take suet or mealworms, while Winter Wrens occasionally feed on crumbs under feeders when they come with flocks of chickadees or other woodland birds. Wrens are gentle birds at the feeder but are bold enough to hold off more aggressive birds like House Sparrows, titmice, and goldfinches.
Garden Tips
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| Meadow Garden with Carolina Rose, Blue Flag Iris, and Bluestar |
The best way to entice wrens into the garden is to create a woodland or woodland edge habitat. Forested neighorhoods and large parks likely already host Carolina Wrens and are suitable for Winter Wrens, while open yards or areas overgrown with brambles are ideal for House Wrens. Carolina and Winter Wrens enjoy wooded areas with canopy and understory, which can be created by underplanting trees or large shrubs with herbaceous plants, smaller shrubs, groundcovers, and by adding vines. Hedges, windbreaks, and tall perennial beds can bring these birds closer to the house and potentially to a bird table. Logs, rocks, tree stumps, and masonry walls add feeding areas, and nest/roost sites for wrens. For the House Wren, plant flowerbeds, low to mid-level shrubs, trellised vines/climbing roses, in open sunny areas or near hedges. This wren may also use nest boxes if you are within its nesting range. A bog garden, small water garden, or riparian buffers (shrubs or trees) along a creek could bring in a migrating Sedge or Marsh Wren.
Plant Choices: Wrens are generalists and are not very picky about plant choices, instead, focus on creating an ideal habitat for the birds to live in. Most woodland trees such as oaks, hickories, sweetgums, magnolias, beeches, birches, and conifers will work for canopy, while dogwoods, redbuds, hornbeam, and birches work for subcanopy trees. Crepe Myrtles, Camellias, Gardenias, and Evergreen Azaleas are always good to mix in with native plants they offer shelter, and flowers for insects, readily available, and are hardy in the Cape Fear Region. In woodland gardens, plant ferns (Cinnamon, Sensitive, Shield etc), and woodland plants such as hostas, bird's nest fern, mayapple, partridgeberry, phlox, or similar plants for ground cover. Wrens also love vines and creepers including climbing roses.
In sunny gardens, almost any flowering perennial or annual will work. I love members of the aster family (zinnias, goldenrods, sunflower, coneflower etc) because these plants are easy to grow, have long flowering periods, and pollinator magnets, while the seed heads bring finches, buntings or sparrows during the autumn and winter.
Fruits: For Carolina Wrens add fruits such as pokeweed, mulberry, blueberry, blackberry, viburnum, beautyberry, dogwood, or magnolia as well as Virginia Creeper/Peppervine. These plants appeal to a wide variety of birds and are either easily found in nurseries or already occur in the garden.
Other Habitat
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| A wren box in a rural garden in Appalachia/Blue Ridge Region |
If you have the space or don't mind a little bit of disorder, allow some areas to become overgrown to start a meadow or old field. In smaller gardens, allowing hedgerows to grow up, and keeping a back area in a natural state can provide bird habitat. Rock piles, simple masonry walls, and the use of logs also adds to the appeal to wrens, treecreepers, and chickadees.
House Wrens and in Appalachia, Winter Wrens may use birdhouses. Both birds use holes as small as 1.5cm or 0.75 inches in diameter. Carolina Wrens are more likely to use wicker baskets, nesting shelves, or repurposed flowerpots, teapots, or watering cans hung in sheltered places or amongst vines.
For water, any simple birdbath or fountain design will work for any of the wren species, although they are more likely to use garden ponds, ground-level baths, or water features close to cover.
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