From the treetops to underground, a healthy backyard wildlife habitat plays host to animals year-round. They need places for resting, birthing and raising offspring. The more nesting options your habitat can offer, the safer and more hospitable it will be for wildlife.
So, where do animals construct their nests? Some, like raccoons, have adapted with relative ease to urbanization by nesting in drainage pipes, open attics, crawl spaces and sheds, when they must. But most animals want an organic environment, like tall grasses, dense shrubs, a meadow, forest or water. A raccoon taking advantage of a storm drain would prefer a comfortable hole in a tree, given a choice.
The same holds true for opossums, who nest in hollow logs, woodpiles, rock crevices and old squirrel nests. The Red Fox likes to nest (“den”) in a burrow dug into a knoll. (Smart as can be, Red foxes often live right in the city wherever the environment is suitable — parks, forested areas, sometimes backyards.) Not to be outdone, a coyote occasionally is discovered living in a city. Coyotes dig tunnels, where they sleep and have their babies.
Other animals, like moles, also nest in tunnels, Most of us don’t want moles in our yards, of course, but even they need insecticide-free vegetation: It’s composted vegetation and plant roots that have contributed, over the millennia, to the topsoil that contains their food — insects, grubs and worms.
Many animals nest near water. If your yard is near a stream, there might be muskrats nesting in burrows nearby. Raccoons, too, want water near their nests. Water fowl generally nest near water. Female Mallards sometimes build their nests away from water and then later walk their new ducklings to water (this brings traffic to a screeching halt on busy streets, but also can lead to the death of momma and her babies.) Not only water fowl have a fondness for water. Some songbirds, like the Tree swallow, nest near water. Bats do, too.
Insects, so overlooked and essential to a wildlife habitat, need places for laying their eggs. There’s hardly a spot in a healthy yard that doesn’t hold an insect’s eggs or offspring in some stage of growth. Some insects even build nests. Honeybees, for example. And ants! Ever picked up the end of a garden hose, only to have hundreds of ants (and their eggs) pour out the end?
Birds are among the most visible animals in our yard. They construct nests in many kinds of places and in sometimes intricate fashion. Some birds nest in caves, hollow trees, thorny thickets or grasses. Many build nests on tree limbs and others, like orioles, suspend their nests from the limbs. Barn swallows use their saliva to “glue” their nest to a vertical surface. Quail nest right on the ground in grasses. Killdeer are sometimes seen nesting on ground with no cover whatever — like in parking lots.
Birds have species-specific requirements for nest-building: 1) an acceptable environment, such as grassland, forest, meadow; 2) suitable nest-building materials; 3) the right frame for the nest, like a hole in a tree, sturdy branches or tall grasses; and 4) for cavity-nesters, an entry hole with the right dimensions and the right height above the ground. Many birds are willing to nest in fabricated housing if it meets their needs. Their nesting materials include twigs, grasses, pine needles, feathers, fur, moss, leaves, and even bits of debris like plastic, paper and string.
A birdhouse (also called a nest box) is civilization’s equivalent to a hollow tree trunk or rock crevice and a wooden platform takes the place of a tree limb or rocky ledge. When forests are cleared to make way for housing, and dead, cavity-producing trees are immediately cut down by homeowners, it’s a daunting challenge for birds to find suitable nesting sites. Bluebirds, for instance, are cavity-nesting birds whose population has dropped alarmingly — up to 90 percent in some areas — due to loss of food and nesting places. So, Bluebird houses, appropriately placed, aren’t merely a convenience for them, but possibly a lifeline.
Some of the other 50 or so North American birds who will nest in houses or on platforms are the Screech owls, some of the woodpeckers, chickadees, swallows, the Wood Duck, Robin, phoebes, House Finch, Tufted Titmouse, Crested Flycatcher and Mourning Dove. Read more about birds who will nest in birdhouses.
Top image of Tree Swallow: Andy Reago & Chrissy McClarren / Wiki; cc by 2.0