Nature Bulletin No. 302-A April 13, 1968
Forest Preserve District of Cook County
Richard B. Ogilvie, President
Roland F. Eisenbeis, Supt. of Conservation
Ten years ago this spring we moved and, of course, put up some nest
boxes for wrens and bluebirds. The two wren houses had entrance holes
just a little smaller than a 5-cent piece, so that sparrows could not get
in, but we made the mistake of putting one of them in a very shady
place. It was never used. The other, a fancy four-apartment affair, we
hung on a hawthorn tree near our picnic table, fireplace and lawn
chairs. A male wren took possession and put a lot of twigs in all four
compartments but when Jenny arrived, several days later, she threw out
all of "his stuff" in the south one and built a new nest of smaller twigs
and soft strips of bark, lined with some grass and feathers. We have
watched them and their descendants raise two broods every spring and
summer. They are part of our family.
The scientific name for the wren means "cave dweller" and, with the
exception of the marsh wrens, they do nest in some cozy nook or cavity.
There was a time when House Wrens lived in forests in tree cavities
such as those made by the woodpeckers but now, like the robin, most of
these fussy saucy little elves have adopted man as their companion. We
are fortunate. Wrens are among the most prolific of all our songbirds,
and about 98 percent of their food is injurious insects: grass hoppers,
crickets, beetles, bugs, caterpillars and weevils. There is a record of a
pair making 1217 trips to feed their young, on just one June day.
House wrens are distributed over most of the United States and
southern Canada. There are three varieties, all found in Illinois but,
being dull brown above and dull gray below, without any distinctive
markings, only an expert can tell which is which. They are about 5
inches long from the tip of the long slender curved bill to the end of the
rounded tail, which is usually perked up over the back. They are very
energetic, nervous and scrappy; do a lot of scolding -- a grating chatter;
and the male frequently destroys the eggs of other birds that attempt to
nest within what he considers his territory. His song is a series of high-
pitched notes that bubble out in a rapid burst and then die away.
Twice each year, Jenny Wren lays from 6 to 10 little brown-specked
eggs in a nest that may be in a bird-box, tin can, or clay flowerpot -- if
these are not placed too high; in the hollow limb of a fruit tree or a hole
beneath the eaves of a house; or in such queer places as an old straw
hat, a glove, the pocket of a garment hanging on a back porch, or a
hollow part of a piece of idle machinery.
Sometimes, in Illinois, the house wren is driven away by a Bewick's
Wren, of which there are several varieties. The two are very much alike
in temperament, habits and appearance, but Bewick's wren is slightly
larger and has a longer tail which it flirts from side to side. It has a
white stripe over the eye and a white spot at each corner of its tail,
although these markings are difficult to see. Its song is much different:
high and variable but clear and melodious, like that of the song
In many parts of the United States, east of the Great Plains and
especially in the more southern states, we also have the Carolina Wren.
Although it usually prefers woodland thickets, brush piles and stream-
bank tangles, it sometimes becomes common around dwellings and
nests in boxes. It is larger and chunkier than the other two wrens, buffy
below and much redder above, with a conspicuous white stripe over the
eye. This wren sings its clear chanting whistle all day, in all weather,
nearly the whole year round.
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Update: June 2012