The Carlisle Mosquito Online

Friday, March 16, 2007


Winter Wren (Troglodytes troglodytes)

© Tim Avery,
On February 7, I was walking east on Westford Street near our house where a small stream flows under the road. I was looking at the sunny edges of the stream bank when I noticed a tiny bird poking around trees roots that overhang the bank. It caught and ate an insect with dark wings, probably a moth. It was a Winter Wren, an uncommon bird in Carlisle, more often heard than seen — and even then, not very often. Winter Wren is even less frequently seen during winter months; only three have been reported during the annual Carlisle Christmas Bird Count since 1973 (data of Ken Harte).

The Winter Wren is dark brown, smaller than the more common House Wren, with a very short tail that it often cocks up vertically towards its head. Its genus and species names, troglodytes, means "cave dweller," which is very appropriate since this bird prefers woodland streams and swamps, with nooks and crannies formed by jumbles of rocks and tree stumps. The nest is built in a natural cavity close to the ground, often in cavities within upturned roots of fallen trees, rotted stumps or stream banks (1). Winter Wrens eat mostly insects, but also eat spiders, millipedes, and sometimes even tiny fish; in winter, they will also eat berries.

Winter Wren is more common in the central and western parts of Massachusetts where there are large undisturbed forests, such as Quabbin Reservoir. In Carlisle we have also seen or heard them at Carlisle Pines State Forest, Estabrook Woods, Great Brook Farm State Park, Towle Land and Town Forest. On August 7, 1999 my wife D'Ann and I saw an adult Winter Wren with three young at the state park near the log cabin; they were along the edge of a rocky spillway where an old mill pond discharges into a ravine. This was the first and only time we have seen a Winter Wren family.

The Winter Wren is also found across Eurasia, where it is the only wren, and is apparently much more common in Britain than it is here. According to Michael Seago (2), the wren in England has adapted well to human habitats such as gardens, hedgerows and farmyards. In fall and winter Winter Wrens form large communal roosts in nest boxes, holes in walls and under roofs. There is one record of a nest box with 60 wrens, and another roost in a house loft that hosted 96 wrens! Seago says, "Squabbling is a frequent event at a large roost; a party of tiny pugilists will 'explode' from the site and then tumble in a bunch trying to evict one another."

The Winter Wren's song is one of my favorites, and hearing it is always one of the highlights of the spring birding season. The song is difficult to describe, being very melodic and complex. However, if you hear it, you are unlikely to forget it. You can find recordings of its song on the web; try the website listed as reference (3). The writer thanks Tim Avery (4) for permission to use his excellent Winter Wren photograph.


1. Kenn Kaufman, Lives of North American Birds, Houghton Mifflin Co., New York, 1996.

2. Michael Seago, Birds of Britain:

3. Tony Phillips, Math Dept., SUNY Stony Brook:

4. Tim Avery:

2007 The Carlisle Mosquito