Category Archives: House wrens

Native wrens offset lack of size with fiercely competitive spirit

 

Nature’s not always neat and tidy. In fact, nature operates with rough-and-tumble mechanisms that, all too often, put some of our favorite birds at odds with each other. Like any other living creature, birds compete for resources — food, water, prime nesting real estate and even mates. Some of those pretty and entertaining birds at your feeder or bird baths have a dark side that isn’t often glimpsed.

When some insight is gained into these behaviors, it’s only human to feel discouraged, disenchanted or dismayed. Nonetheless, some recent emails have reminded me to look at some of these more distressing incidents as teaching moments.

Joy Stewart emailed me asking for advice on a problem with rival nesting birds in her yard.

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Photo by Jean Potter • A house wren brings a delivery of food to waiting young.

“I have a total of 10 bird houses in my yard,” she wrote. “They are sized for a variety of bird species, and most years nearly all are filled—usually wrens, bluebirds, tree swallows, nuthatches or finches.”

At a recent get-together, she talked with a woman who also puts out bird houses and works hard to attract birds. “She talked at length about how bad house wrens are and how they destroy or kill bluebird eggs and babies,” Joy wrote. “She described how these wrens had just killed a house full of baby bluebirds. The woman also said house wrens are not native to this country.”

Joy noted that she usually tries to keep track of these types of issues, but the woman’s claims were all shocking news to her and made her wonder if such cutthroat competition might explain why her bluebirds seem to have absented themselves from her yard.

She ended her email by asking two questions. “Is the problem as bad as it sounds?” Joy inquired. “Also, how do I now work to get rid of the house wrens that have been coming to my two wren houses for over 10 years?”

She noted that just permanently taking down the houses would likely not work. “If nothing else, they will just move into the slightly larger houses,” she noted.

I replied to Joy’s email, noting that her friend is partly correct, but has confused house wren and house sparrow. From her description, I also noted that it appears she has house wrens in her yard.

The house wren is a native bird; the house sparrow is not a native bird, but was introduced into the country. Its true origins are Africa/Europe.

However, as cavity-nesting birds, both the sparrow and the wren compete with bluebirds. Legally, Joy can take steps to “control” house sparrows. As non-native birds, they are not protected.

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Photo by U.S. Fish & Wildlife Service • House sparrows, such as this female, are non-native birds that pose a serious threat to native cavity-nesting birds such as Eastern bluebirds.

However, the house wren is a native bird. I also happen to like house wrens. They have such bubbly, happy songs, and they’re good parents. They can raise as many as 10 young in one nest box.

Unfortunately, both the wren and the sparrow engage in ruthless behavior when it comes to nesting. Both species will evict bluebirds and other birds from boxes. They will even destroy eggs and young. Bluebirds can and do fight back, but despite their small size, house wrens are very feisty.

House wrens like brushy habitat that offers a lot of cover. I suggested Joy might consider trimming back or eliminating brush and hedges. Open space is also more attractive to bluebirds. Of course, chickadees and nuthatches also like brushy habitat and woodland edges, just like the house wrens.

It’s complicated, but I come down on the side of our native birds. House wrens have their place, but house sparrows should never have been in this country in the first place. I advised that Joy leave the wren boxes available to forestall the wrens deciding they have to fight other birds for a box. At the same time, I would not place any other boxes close (at least not within easy view) of the wren boxes, as wrens are very territorial.

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Photo by Bryan Stevens • Eastern bluebirds compete with native cavity-nesting birds such as house wrens and tree swallows for prime nest locations. Non-native birds, such as European starlings and house sparrows, can out-compete native birds for limited resources.

In response to a follow-up query, I suggested that placing the boxes completely out of sight would be the best rule of thumb. Try to have a building, a wall, or perhaps a large tree blocking the wren boxes from other boxes. At least this way, perhaps the adult wrens won’t be viewing the competition. It would be advisable to keep as much space between the wren boxes and the boxes meant for other birds as is practical and possible.

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An email from another reader likely involved a nesting wren. These small birds are rather notorious for choosing odd nesting sites. I’m thinking it is that tendency that explains Vivian Tester’s recent email asking for some suggestions for a somewhat unique problem.

“I’m looking for advice,” Vivian wrote. “I have a bird that has made a nest on my car windshield. I have driven the car a few times and she will fly away when I start the car, but I don’t want to do anything to harm her or the eggs.”

The situation had her baffled. “How long should it take for the process of laying eggs and them hatching and leaving the nest?” Vivian asked.

She noted that she had not been able to see any eggs. She added that the nest’s construction starts at the windshield and goes into the area under the hood. “I haven’t tried to open the hood in case it would destroy the nest,” she wrote.

Surprisingly, Vivian said the same thing happened last year but she just kept removing the nest. “I’m just not sure what I should do,” she wrote.

In my reply, I told Vivian that it sounds like she has a wren or perhaps a sparrow, and it can take 12-16 days for the eggs to hatch. The young must then spend another 10-12 days in the nest, so it could be at least four weeks for the entire process.

I suggested that, unless she could go without her car for a month, she should open the hood and gently remove the nest somewhere close by. A box or crate could hold the nest and the parent birds are likely to simply move from the car over to the new location for the nest. The parents are more attached to the nest itself than they are your car.

I admitted that I was sort of “winging” it on this problem. While a car is an odd choice for nesting, I’ve heard of birds such as swallows that nest on boats and then follow the boats along their river routes.audubon-ix-songsters-and-mimics-house-wren

After I responded, Vivian emailed me back. “I wanted to update you on the bird nest,” she wrote. “I did move it today into a hanging basket just above my car.”

The nesting bird flew away when Vivian opened the hood. “I am hoping she will return since I did see four little eggs in it,” she wrote.

I believe Vivian’s bird is probably a Carolina wren. I’ve observed these wrens, a slightly larger relative of the house wren, nesting in an old apron my grandmother used as a bag for her clothespins, as well as a plastic shopping bag hanging from a nail in my garage. A pair also once tried to nest in the exhaust vent for my clothes dryer.

Worldwide, there are about 80 species of wrens. All but one of the world’s wrens are confined to the New World. A variety of common names describe the various species with some creativity, including such monikers as tooth-billed wren, flutist wren, white-headed wren, sepia-brown wren, fawn-breasted wren and moustached wren.

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Bryan Stevens lives near Roan Mountain, Tennessee. To share a sighting, make a comment, or ask a question, send email to ahoodedwarbler@aol.com.

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Territorial nature of house wrens brings these tiny but feisty birds into conflict with their neighbors

 

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Early naturalist and artist John James Audubon famously painted a family of house wrens utilizing an old hat as a nesting location.

Birds don’t waste much time getting down to the business of nesting each spring. I’ve observed baby robins and bluebirds that are already out of the nest. At home, I have nest boxes occupied by Carolina chickadees, Eastern bluebirds and tree swallows. Unfortunately, for a variety of reasons, nesting attempts don’t always end successfully.

Kathy Shearer, who lives in Emory, Virginia, wrote me last month about a problem affecting her nesting bluebirds.

“I had an active bluebird nest with five eggs until yesterday, when I discovered the shell remnants on the ground beneath the pole,” she wrote. “One was clearly drilled through.” Kathy sent along a photo showing the damage.

“I suspect house wrens, which have followed the bluebird nests for several years, building their own nests in the same box. However, they always let the bluebirds raise two clutches before moving in, until now,” Kathy wrote. “Is there any way to combat these wrens?”

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Photo by U.S. Fish & Wildlife Service/Dave Menke House wrens make dutiful parents, often tending a brood of as many as eight young.

Kathy’s question presents a definite quandary. With invasive birds, like house sparrows and Eurasian starlings, many bird experts recommend tearing out their nests. Some even suggest disposing of eggs and young. It sounds cruel, but native birds like Eastern bluebirds are at a disadvantage when it comes to competition with these non-native invaders. House sparrows and starlings were never meant to be part of the fauna of North America. Human actions introduced these birds into an environment unprepared for the consequences of the intrusion.

That’s what makes the problem with house wrens a difficult one to solve. The house wren is a native bird that is as much a legitimate part of the environment as bluebirds, tree swallows or other cavity-nesting birds.

Anyone who has ever observed tree swallows and bluebirds competing for a nest box knows that these birds are fierce in their struggles for a nesting location. The house wren, however, uses another approach. These small wrens are stealthy and somewhat ruthless, although both of these terms are something humans have applied as labels to this bird’s natural behavior.

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Photo by Jean Potter                                              A house wren checks out a nesting box. Males will often build “dummy nests” to provide females with a choice of nesting locations.

Known by the scientific name of Troglodytes aedon. In Greek myth, Aedon is a woman changed by Zeus into a nightingale, a bird famed for its song. A troglodyte is a cave-dwelling individual. So, roughly translated. the house wren’s scientific name is “cave-dwelling nightingale,” which emphasizes the penchant of the house wren for producing a bubbly, persistent song all out of proportion to the bird’s tiny size. The “cave-dwelling” description comes from the habit of house wrens, as well as other members of the wren family, to skulk near the ground for exploration of nooks, crannies and crevices in search of food.

The house wren arrives in the region just in time for the start of the spring nesting season. Although it is a native bird, this wren often fails to win favor because of its habit of damaging the nests of other cavity-nesting birds such as Eastern bluebirds and Carolina chickadees.

“To a house wren, almost any other nesting bird in its territory threatens competition,” wrote John Eastman in his book, “Birds of Forest, Yard and Thicket.” Eastman, a wildlife biologist and naturalist, emphasized in his chapter on the house wren the territorial nature of the bird. Not only will house wrens puncture the eggs of other birds, they will also kill young birds that are still confined to the nest. Once a pair of house wrens adopts a nesting site, they may remain loyal to it for many years. According to Eastman, these tiny birds display a powerful fidelity to nesting locations from previous seasons.

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Photo by Bryan Stevens                                      The two-toned Carolina wren is, for the most part, a kinder and gentler neighbor to other birds in comparison to the related house wren.

I did offer some advice to Kathy, although I cautioned that wrens can be tough to deter since they are extremely territorial. However, they don’t like open spaces as much as bluebirds. I suggested that she make sure her nest boxes are not located near buildings or trees, which could encourage house wrens. House wrens feel most confident when there are thickets, hedges or other thick cover available.

Alternatively, she could provide more nest boxes. House wren males will build multiple “dummy” nests in his attempt to attract a mate. These nests must be approved by the female. Once she makes her selection, she will line the nest with softer materials and then lay her six to eight eggs. If Kathy provides enough boxes, the wrens in her yard might leave the bluebirds alone. I realize that is a big “might.”

Kathy responded with another email after I offered my suggestions. She noted that she lives in a wooded area, so finding open space is difficult. “This bird box is in the middle of the garden, the only open space we have, and has been successful for many years,” she wrote.

Kathy plans to move the box and to put up a second one in the woods that might satisfy the wrens. She also did some of her own research and came across the suggestion of building a guard over the entrance that blocks it from view. “Might give that a try,” she wrote.

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Photo Courtesy of Jean Potter                                                A Carolina wren creeps along a fence. Other wrens in North America include Bewick’s wren, marsh wren, sedge wren, cactus wren, winter wren and rock wren.

As much as I hate it when these conflicts arise, house wrens are a native species of bird. That sets them apart from birds like house sparrows and starlings, which are not native. These wrens are small birds, so their aggressive nature is probably a survival adaptation that has served them well as they must contend with larger birds for limited resources.

House wrens are not as photogenic as bluebirds, but they have a lot of traits that make them worth observing. First and foremost, this wren produces an enthusiastic and energetic song. The parents will also rid yards and gardens of a great many insect pests as they work to keep six to eight hungry babies fed. Every wild creature has its place, so I try to offer equal respect to them all.

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To learn more about birds and other topics from the natural world, friend Stevens on Facebook at https://www.facebook.com/ahoodedwarbler. He is always posting about local birds, wildlife, flowers, insects and much more. If you have a question, wish to make a comment or share a sighting, email ahoodedwarbler@aol.com.