Bayou-Diversity (17 May 2020) Spring is a busy time for most birds in northeast Louisiana. Whether they are year round residents or just returning from wintering areas in Central and South America, most are involved in nest building of some sort. Nests of course are where birds lay eggs and are as varied as the many species that frequent our locale. They can be found from ground level to the tops of the highest trees. They can be as simple as a depression in the leaves or as complex as a finely woven bowl of spider silk and lichens.
Most people think of the typical nest as the familiar cup-shaped structure built by many songbirds. Red-tailed hawks and great blue herons however build platform nests of sticks and twigs; white-eyed vireos build hanging cup nests from a tree fork; barn swallows and phoebes plaster their cup nests to a vertical wall (usually under bridges in our area); and Baltimore orioles weave bag like nests suspended from branch tips.
Nest locations also vary. Killdeer lay their eggs on the bare ground of gravel parking lots or the flat roofs of buildings. Vultures build nests in hollow logs or abandoned structures. Kingfishers and bank swallows burrow into the sandy banks above our waterways to nest. Several species of woodpeckers excavate holes in dead trees. Other birds like the tufted titmouse, bluebird, prothonotary warbler, and wood duck also nest in cavities created by woodpeckers or other animals. Most nests are inconspicuous or camouflaged for the protection of the incubating parents and eggs or nestlings.
In constructing a nest most songbirds use a foundation of twigs interwoven with grass, strips of bark, dead leaves, pine needles, mosses, animal hairs, or feathers. Robins and wood thrushes use mud to glue their nests together. Cliff swallows build their nests entirely of mud. Chimney swifts and hummingbirds secrete sticky saliva to cement nest materials. For unknown reasons the crested flycatcher and tufted titmouse routinely use cast-off snake skins to line their nests. Other odd materials occasionally show up in bird nests. A five-dollar bill was found braided into a brown thrasher’s nest, and a raven in Texas built a nest entirely of barbed wire.
Bird nests in Louisiana vary from the one inch diameter hummingbird nest in a white oak to a thousand-pound bald eagle nest in the fork of an ancient cypress. My favorite is that of the common and perpetually busy Carolina wren. They are infamous for stuffing every available orifice with nest material. Not long ago researchers at Barksdale Air Force Base found a wren nest in a deactivated ICBM missile. Now is that optimism or what? (Adapted from Bayou-Diversity: Nature & People in the Louisiana Bayou Country by Kelby Ouchley; LSU Press)