Most folks know Eastern bluebird nests in cavities (for a thrush species, that is actually unusual) and most choose the nesting boxes we have supplied them. The house wren (Jenny wren) also finds some unusual cavities, or your wren boxes, to nest. Take a short ride to one of our county or state run parks and many of the bluebird boxes there also offer dozens of tree swallows man-made cavities.

But I’d like to introduce you to a few larger birds that use cavities for their nesting. I’m referring to belted kingfishers, wood ducks, hooded and common mergansers, and even the rather large barred owls.

Of the group I mentioned, only one “builds” their own cavity. The belted kingfisher uses its rather large beak for more than catching small fish. It finds a steep bank, usually a silt or clay composition, and excavates a tunnel more than 3 feet long. Sometimes this cavity isn’t even near water.

Our wide variety of woodpeckers nest in cavities that they construct. Fortunately, for chickadees, tufted titmice, tree swallows and even flying squirrels, they use that hole one year. Thus these smaller songbirds have ample sites from which to choose.

Wood ducks, hooded mergansers, and common mergansers, being considerably larger than our songbirds, have to find natural cavities to nest. Often when a tree top or large limb snaps off, a few years later a rotting cavity remains. I sat along Lizard Creek over a month ago and watched a pair of common mergansers wing their way past me a number of times. Twice the hen landed in a large tree to inspect the snapped-off top, checking out its suitability.

You may find it interesting that their young are precocial and active within hours after hatching. Mom wood duck or merganser coax their young to jump, and these little 3-inch fluff balls pop out of the nest cavity that could be 70 or more feet in the air. They are so light they seldom get injured in their tumbling fall to the ground.

Barred owls, an inch or two smaller than great horned owls, nest in cavities, too. They live in forested lowlands or deep in a forested area, but most often near a water source or even a swamp. The habitat needs to have large trees because the nesting cavity opening must be about a foot wide and sometimes even a few feet deep. They have been seen nesting in old hawk platform nests but they are then more likely to be preyed upon by the great horned owl.

They, like the screech owl, add little nesting material to the cavity and can lay one to five eggs there. The key to their success is finding a variety of food sources (thus the preference for habitats with water) and older trees whose girth would provide cavities large enough for them to nest.

You can find each one of these species nesting here in the Times News region; so get out there.

Test Your Outdoor Knowledge: You are fishing in the Lehigh River and catch an American eel; it was born in: A. the Delaware River, B. Maine’s coastal waters, C. the Sargasso Sea, D. the Delaware Bay.

Last Week’s Trivia Answer: Each time a rattlesnake sheds its skin, it adds a rattle. It is possible a rattlesnake could shed two or three times a summer or, in older snakes, some rattles could have broken off. So the rattlesnake I found with nine rattles isn’t necessarily 9 years old.

Contact Barry Reed at breed71@gmail.com.