House wrens may be tiny birds, but they have big personalities
As birds go, the house wren (Troglodytes aedon) is on the small side. With a range in body size from 4.5 to 5 inches, the house wren is comparable to the American goldfinch, the chipping sparrow and most warblers. There are a few birds that are smaller, but not many.
Any shortcoming in stature is more than compensated for in the personality department, however. House wrens are some of the noisiest birds, not just because their voices are loud but also because they never seem to stop singing.
An optimistic male who is trying to attract a female to his nest will just sing and sing and sing a song that has been described as “a stuttering gurgling song, rising in a musical burst, then falling at the end.”
House wrens are very territorial, and once they occupy an area they will usually raise two and sometimes even three batches of babies in a given year. As a result, they jealously guard their space. In an effort to maintain a buffer zone of no neighbors, the male house wren will actually build a collection of “dummy” nests in every available location in his territory. This, I think, prevents other birds from setting up shop nearby, but it may also offer the female house wren the widest possible selection of nest sites.
Two weeks ago, I noticed that the male wren in my yard had taken up residence in a box at the top of my field. A pair of tree swallows had successfully used this box in June. I managed to take some photos of the male and female as they worked on their nest. Wren nests are quite distinctive, and it was fun to watch the birds put it together.
Whereas bluebirds build simple grass nests and swallows build grass nests decorated with feathers, house wrens build very bulky nests made of small twigs. The nests usually fill the entire box so there is only a small passageway that extends to the back wall of the box and then almost all the way down to the floor.
Some of the twigs that are selected are large enough to be described as sticks, and the amount of effort required to transport these items and get them inside a nest box has to be enormous. The occasional “walking through a doorway with a surfboard” moments that unfold must be hilarious, but I witnessed the reasoning behind building such a nest first-hand just this morning.
I looked out at the box and noticed that a crowd of young starlings was perched on it. I then saw the starlings taking turns sticking their heads in the nest hole. I was worried that the starlings might be able to reach the eggs that were hiding within, but I am happy to say that the eggs survived. When I opened up the box, I saw that the eggs were safe and sound beyond the reach of curious teenage starlings.
Here a short time
House wrens eat insects and other invertebrates but nothing else. As a result, they need to migrate to avoid the cold, foodless northern winter. For house wrens, this requires a trip to Mexico, which means that the chicks that soon hatch will have to grow, fledge and learn to take care of themselves well enough to migrate to Mexico in the next three months. I always feel like summer goes by quickly, but the little wrens will think that summer lasted for just a day or two.
Bill Danielson is a professional nature photographer and author living in Altamont. Contact him at www.speakingofnature.com.