Woodpeckers excavate cavities for nesting and roosting. These tree hollows are also essential to birds that cannot chisel out their wood-lined nesting sites. Among the birds that nest in abandoned woodpecker holes are backyard favorites such as tufted titmice and eastern bluebirds. Unfortunately, these cavities are highly prized by non-native birds such as the European starling.
The truth of the matter is in most parts of state, demand for natural cavities far exceeds the availability of such natural nesting sites. When an aggressive alien bird such as the starling competes with these a native bird for the same cavity, the starling invariably wins out, often leaving the native bird without a place to nest.
It is a sobering fact that starlings usurp half of all cavities created by red-bellied woodpeckers.