You can tell the creature by how it nests

Nature lovers tour South Park to spy on bird residences
December 5, 2011 12:00 am
  • Daniel Krapp, 8, of South Park, listens Saturday to John Doyle, a naturalist with the Allegheny County Parks Department, talk about the animal hair used to line one of the bird nests collected during "Bird Nests: Exposed and Explained" held at South Park, near the Oliver Miller Homestead.
    Daniel Krapp, 8, of South Park, listens Saturday to John Doyle, a naturalist with the Allegheny County Parks Department, talk about the animal hair used to line one of the bird nests collected during "Bird Nests: Exposed and Explained" held at South Park, near the Oliver Miller Homestead.
Click image to enlarge

Share with others:

While some birds build new nests each year because of winter damage or parasites, other species reuse the same nesting spots and get rid of parasites creatively: layering cedar bark and leaves in open nests, or smearing pine sap and insects around the entrance of cavity nests, according to Mr. Doyle.

Many birds are very specific about what nest sites to use -- so-called cavity builders such as chickadees and bluebirds that use holes in rotted trees and fenceposts, for instance, like an eastern or southern exposure to keep out rain and let in sunshine to help warm their eggs. Bluebirds get even more particular. They want boxes about 20 feet inside a field, not on its edge, he said.

In the trees along Catfish Run, Mr. Doyle and his group found several hawks' nests and then, in a snag, a rotted tree with several holes. The higher hole, where the wood was softest, probably was a chickadee nest while the lower cavity probably was the nest of a pileated woodpecker or screech owl, he said.

Then, hiking up a hill into the woods, the group found a round ball of sticks and grass caught in a bramble along the woods' edge, likely the nest of a cardinal or a catbird. When the thicket was leafed out in the spring and summer, it would have been almost impossible for predators to see, Mr. Doyle said.

If nest-spotters can get close, a nest's lining is often the best identifier of its occupant.

Catbirds like rootlets, while cardinals and bluebirds prefer fine grass for their linings. Goldfinches use thistle down, while chickadees enjoy a moss-filled nest. And if you see mud inside a nest, a robin almost certainly has been hard at work, scooting its body around in the mud to plaster the "walls," Mr. Doyle said.

Vireos use spider webs to hold their grassy materials together and lots of birds decorate: eagles with flashlights and bicycle rims, cat birds with napkins, cellophane and shoestrings. And sometimes, people provide even more personal building materials -- like when titmice decide they need some fur to go with their snakeskin.

"Some guy will be sleeping on his porch and it will start picking the hair out of his beard and out of his hair," Mr. Doyle said. "It's interesting behavior, but I guess it's got to get material somewhere."

Amy McConnell Schaarsmith: aschaarsmith@post-gazette.com or 412-263-1719.
First Published 2012-02-09 14:11:19
PG Products