Loyal reader Fritz Hopfinger of Brooklin emailed me recently about his loyal German shepherd, which has been surrendering fur to a tufted titmouse. The bird visits the dog daily, plucking fur and carrying it to her nest hole. Fritz conveyed that the bird isn’t timid, and the dog doesn’t mind. Would I like to see pictures? Sensing a chance to win that elusive Pulitzer Prize for birding journalism, I naturally said yes.
A few days later, the photographic evidence arrived. Somewhere, in a tree cavity nearby, there are some baby titmice snuggling warmly in a fur-lined nest.
Nest building is one of the wonders of the avian world. Not only are they a home for chicks, but nests often are used as social signals. A male marsh wren builds several dummy nests just to prove his worthiness. Eventually, the female chooses the nest — and the male — she desires and finishes the job. She may even keep the male — but build her own nest.
Pileated woodpeckers stay in faithful pairs year-round. Nonetheless, spring is a time for the male to prove himself, and he tends to go a little nuts, whacking square demonstration holes into numerous trees before the pair settles on a new home.
Some nests scarcely deserve the title. Common and arctic terns merely scrape the soil before laying their eggs. Puffins dig burrows in rocky crevices, but their cousins, the razorbills and murres, just lay their eggs on a bare ledge. The eggs are oblong, so if they roll, they roll in a circle instead of off the cliff. Peregrine falcons just scrape a spot on a precipice. Woe to the nestling that sleepwalks.
Meanwhile, eagles, ospreys and herons make enormous stick nests meant to be used year after year. Some are so large that they threaten the support they are built upon.
Some birds surprise you. One doesn’t think of gulls and shorebirds as tree nesters, but in Canada, the diminutive Bonaparte’s gull nests in spruces near fresh water, and solitary sandpipers are tree nesters. The marbled murrelet is in the same family with puffins, but it nests in the 200-foot treetops of old growth forests in the Pacific Northwest.
Then there’s the belted kingfisher. It nests in a burrow dug into a sand pit, sometimes distant from the water where it forages. Wood ducks and hooded mergansers nest in tree cavities. It’s always odd to see a duck standing high on a tree limb.
Swallows use every nest-building strategy there is. Tree swallows nest in cavities. Bank swallows nest in burrows. Rough-winged swallows do both. Cliff swallows attach self-supporting mud huts under eaves and bridges. Barn swallows build nests under structures, often in the same places as cliff swallows. They also use mud to help bind the nest together, but their nests need support under the floor.
Nest weaving is an art. Robins appreciate string and twine left in the backyard. A useful length is 3 to 8 inches. Blue-headed vireos often use strips of birch bark. Many species use sticky cobwebs to bind nests together. One day in May, many years ago, I was sitting on a porch, reading a book. I must have been pretty still, because a female black-throated green warbler landed on my chair and hopped up onto my shoulder to reach the cobweb behind me. She carried it off, apparently unaware she had just perched on a human.
Baltimore orioles take the art of nest building to a new level. Their hanging nests resemble large socks. First, the female weaves long fibers over the branches. Then, she pokes the mass of fibers with her bill until it’s sufficiently tangled to simulate knots. Springy fibers are added to reinforce the bowl. Eventually, down and feathers line the inside. It takes a week or more to build each one.
Nest lining is another art. Like the titmouse, the closely related chickadee likes to line its nest with animal fur. Pet hair left in the yard is a boon. Even your own hair clippings are valued. Cattail fluff, moss, lichens, pine needles, grass clippings and shredded paper often end up lining a nest.
Waterfowl frequently pluck their own down to line a nest. Common eiders are legendary for the insulating properties of their feathers. Until modern synthetics came along, eider down was considered the lightest, warmest stuffing for winter clothing and sleeping bags.
I could learn a lot from this experience. May I be as bold as the titmouse, and as mellow as the shepherd.
Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at duchesne@midmaine.com.