The Banded Wren’s (Thryothorus pleurostictus) dormitory nests – characteristics and comparisons with breeding nests

The banded wren inhabits the tropical dry forest from Mexico to Costa Rica. These birds belong to a small group of wrens that construct both breeding and dormitory nests, a unique characteristic. During the breeding season (May-August) in 2007, we located 200 breeding nests and over 400 sleeping nests. The breeding nests, usually found in ant-defended acacias, are large, conspicuous structures. The dormitory nests, found in a variety of substrates, are smaller and less substantial. I will describe the dormitory nests in detail, including the similarities and differences with breeding nests, and will highlight possible reasons to explain the unusual behavior of making and using dormitory nests.