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Allen Rhodes
To birders, the variety of sizes, shapes, colors, songs, habitats and behaviors of our feathered friends are fascinating and account for much pleasure. However, if you go a little farther and search carefully, you will find another much-varied dimension of the bird world – their nests.
Birds’ nests are constructed from a variety of materials in a variety of locations. They range from carefully constructed, complex structures of grass, straw, sticks or mud, to a snug, wood-walled structure, to a simple bare spot on the ground. Some birds, such as the brown-headed cowbird (Molothrus ater), do not build nests. Instead, they are parasitic and lay their eggs in other bird’s nests
The photograph above shows the tiny, camouflaged nest of a hummingbird with its outside covering of lichens. This nest, which was photographed by Forrest Mims along Geronimo Creek in Guadalupe County, Texas, is most likely that of a ruby throated hummingbird (Archilocus colubris), as they are the most common nesters in this area. This nest may weigh only an ounce, but it represents substantial effort on the part of the parents and provides the cover and concealment for their clutch of tiny eggs.
A good example of a nest which required minimal effort on the part of the parent birds is the “nest” of the common nighthawk (Chordeiles minor) from LaSalle County, Texas, in the adjacent photograph. The nest site was found while I was searching for Indian artifacts and would likely not have been noticed but for the parents’ swooping and calling as I entered the opening in the brush. Their behavior, meant to distract, alerted me to the possibility of a nest site, and after about 15 minutes I found it.
The two eggs, which are easily overlooked, resemble smooth stones. On a second visit to the nest site nine days later, I could find no sign that there had ever been a clutch of eggs. It is possible that a predator, such as a snake, raccoon, skunk, or feral hog, could have eaten the eggs or fledglings, but there were no signs to indicate what happened If you have driven along highways in much of Canada and the United States during summer, you have probably noticed swallows swooping around overpasses and perching on utility wires, sometimes in large flocks. These may be either cliff swallows (Petrochelidon pyrrhonota) or barn swallows (Hirundo rustica).Cliff swallow nests are finely constructed of mud and stuck to a horizontal surface or on a ledge under a bridge, culvert or overpass. They are occasionally found on buildings.Cliff swallow nests may be distinguished from those of barn swallows by construction (overhead cover and tubular entrance) and location. The cliff swallow nest shown here, which was photographed in Guadalupe County in South-Central Texas, has a characteristic roof, a circular entrance and is nearly tubular in shape.Barn swallows generally build on manmade structures, such as barns and under porches and carports. They may use bridges and overpasses as well. Barn swallows are tenacious, and, once they decide they like a location, they are hard to chase away. The barn swallow nest shown here was photographed in Guadalupe County, Texas. The nest is an open cup without a tubular entrance that is stuck against a horizontal surface or, perhaps, built on a ledge. Both cliff and barn swallows have adapted to man’s influence on their environment, willingly building their nests where buildings and other structures suit them.The cactus wren (Campylorhyncus brunneicapillum) is the largest wren found in North America. It is identified by its size, distinct white eye-stripe and overall streaked appearance. It builds a football shaped nest of grass and straw with a side entrance. The nest shown here was neatly built between the pads of a prickly pear cactus.
This nest was photographed in LaSalle County in South Texas. It demonstrates the wren’s accommodating nature, for it was built near an equipment shed adjacent to farm equipment and a grain storage facility. Other than fussing at the ranch workers as they moved by or through the area, the wrens went about their business and raised their brood.Woodpeckers chisel out holes in trees, utility poles and even buildings and use the cavity for their nests. The hole shown here in a mesquite tree in LaSalle County, Texas, was originally made by a golden-fronted woodpecker (Centurus aurifrons).
In subsequent years, the cavity has been used by other species, including wrens and flycatchers
