The sapsucker breeds in young, northern deciduous forests. Redheadeds prefer mature hardwood forests with dead trees and nut crops. Older stands of oak are its habitat choice.
Secondary cavity nesters rely on previously excavated holes. Chickadees, titmice, and nuthatches are examples.
Bluebirds used to rely heavily on old woodpecker holes, but numbers began to decline when starlings and house sparrows competed with bluebirds. Luckily for many bluebird lovers, nesting boxes mimic the nest cavity, and the birds readily take to it. Bluebird trails now exist in many communities and the population is doing well.
Similarly, purple martins used to rely on cavity trees along forest edges, rivers and open fields but have since moved almost exclusively to human-made structures for nesting. You’ ve probably seen the white, round, plastic houses looking like gourds hanging together. Installed near mowed fields or lakes, martins soar back and forth as they feed on insects that rise from both surfaces.
Other species like the greatcrested flycatcher, prothonotary warbler, and tree swallow take advantage of both tree cavities and nest boxes that mimic cavitylike conditions.
It isn’ t only small songbirds that utilize tree cavities. Waterfowl like wood ducks, hooded merganser, and the common merganser use
Screech owl. photo by Leah Baker
tree holes and waterfowl nesting boxes. The American kestrel, barred owls, barn owls, and eastern screech owls use available tree cavities and nest boxes for roosting and nesting.
And many readers know about our native wildlife like squirrels, raccoons, bats, and opossums that also rely on abandoned cavities for shelter and rearing young.
A professor of mine once used a stick to beat on a tree with a prominent hole overhead.“ We’ ll see who’ s home,” he said. After several loud taps, poking a head halfway out, a sleepy raccoon looked around, then retreated inside. I used this same technique on many hikes over the years. Sometimes it was flying squirrels, screech owls, and bats that halfway emerged. Disturbed for a few seconds, they disappeared back inside. My hikers enjoyed the spectacle.
A reason for cavity nesting birds declining is a lack of dying and dead trees left standing on the landscape. No question, dead trees pose a threat to homes, buildings, and places where people gather, but also offer a great way to promote wildlife. To combat this problem, city planners have erected artificial nesting boxes, often taken on as a community project, or by a local conservation club. Dead trees in our woods attract
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