When we think of birds nesting, we often picture something like this:
In fact, most birds do not build their nests on high tree branches.
Some birds nest on the ground, taking cover in tall grass.
Some birds, called primary cavity nesters, peck a hole in a tree and build their nest inside it. Other birds seek out holes used by primary cavity nesters in previous years. These birds, known as secondary cavity nesters, are the species that will use birdhouses.
And many birds nest in shrubs. They look for dense vegetation, three to six feet above the ground, that will provide a safe place to raise their babies. It is exactly this shrub layer that is missing in an undervegetated yard. When appropriate places to nest are not available, birds may not nest at all, putting the survival of their species in jeopardy.
A shrub layer is not difficult to establish. Young shrubs can be planted near each other – accounting for their mature size – to grow into a dense grouping. In a few years, they will provide a place for birds to nest, as well as flowers for pollinators, privacy screening for people, and a host of other benefits.