5/20/04 — NESTS

Now that we are really into spring, those who follow bird activity realize that this is the season for bird nesting. I find it interesting that there is a wide spread between the dates at which birds nest.

For instance, great horned owls begin this process as early as January, even here in the North where it’s cold and snow falls frequently. I’ve seen photos of female owls sitting on nests with a blanket of snow over them. It takes these birds a long time to rear their young, which is why they need such a lengthy time for the project.

Not only is there wide variance in the nesting dates of different species, there is also vast dissimilarity in their modus operandi. Some birds are very secretive about their activities and choice of nesting sites, while others make no effort to hide their actions. I place chickadees in the former group. They are early nesters, and they are adept at finding tiny holes in which to lay their eggs, incubate them and care for their young until they are ready to fledge.

I’m almost positive that a hole near the base of a rhododendron by my back door is where this is all happening, but I never actually catch a chickadee in the process of coming out of or going in what appears to be a likely hole. All I ever see is the shooting up or diving down of the birds. I guess I need more patience and a blind where I could sit and watch and wait ... and wait.

Contrast that sort of nest with one of an osprey or those of other large birds. For instance, a raven was recently spotted carrying a stick to a telecommunications tower at the Verizon building in Concord. What made this sighting especially unusual is that ravens usually nest in rural areas rather than in a town. Other urban reports include red-tailed hawks nesting on a fire escape at Boston University, on a caged light post, in the cupola of the Harvard chemistry building, in the tower of the Perkins School of the Blind in Watertown, as well as on the light poles surrounding Harvard's lacrosse field.

Although great horned owls build large nests, they are often difficult to find, and once leaves are out on the trees, harder yet. These owls don’t build their own nests but usurp those previously made by red-tailed hawks, great blue herons, crows, bald eagles, osprey and even squirrels. They don’t add much new material; they just clear a hollow in the center and are ready to go. What could be simpler?

Mourning doves are early nesters, and while they do their own construction work, they are not particularly fussy. All they need is just a platform of some loosely-placed twigs, no lining of grass or weeds, often in evergreens but also in tangles of shrubs or vines — or maybe even a deserted robin’s nest. Usually they lay only 2 eggs but have two or more broods.

Robins make what everyone considers the real essence of nests, but we reach this conclusion because most of us have had the opportunity to observe a robin incubating eggs, then feeding the young. And, too, robins are found in a great variety of locations: on farms, in cities and towns, open woods and in our yards. I’ve seen pictures of robins that built their nest on a front door wreath, so, obviously, whatever works is all they need.

The thought of the wreath brings me to the birds that a lot of folks find nesting in their hanging planters. Nearly 100% of the time, these are house finches. Yes, it is all right to water your plants; just don’t overdo the amount of water. House finches are seemingly placid birds with not too many cares, but they do know how to choose a beautiful, colorful site while waiting out the processes of incubation, feeding and training of their young.

Of course, everyone enjoys seeing a Baltimore oriole’s nest, although finding one before the leaves are off the trees is really a matter of good fortune. Their intricately woven, deep pouch made of plant fibers, hair, yarn, string is always a wonder. How can they do that? Actually, it’s not they — it’s she. The female does most of the work.

Some birds cooperate in nest building. Although female tree swallows fill the nest box or other cavity with grasses, it’s the male who contributes the ne plus ultra, the final piece that makes it truly a tree swallow’s nest: a white feather. I’ve watched a male many years in a row struggle to get that long white finishing touch through the hole. Eventually, he figures it out, and voilá! the nest is ready for use.

Have you ever wondered why we don’t see more nests once the leaves are off the trees? Many blow down or get washed away in our various storms, but the birds themselves do not destroy them. Some nests’ parts are stolen (recycled?) by other birds once a nest has been abandoned. The large stick nests of owls, hawks and eagles endure best, but we don’t really know what happens to those that are in conifers or in cavities. And, unless we spend a lot of time during the winter in wood lots, we’re missing the sites of many a nest.

Won’t you please send your observations of nesting activity to me? I’d like to share them with other readers.

Please send your comments and anecdotes about birds to me in care of the Cape Cod Times, 319 Main Street, Hyannis, MA 02601 or, if you use email, to emiller@seepub.com. I regret that because of an overwhelming amount of mail, I cannot respond to each of you personally. However, I have added a Frequently Asked Questions (FAQ) section to the web page with my current and past bird columns, now found at http://home.comcast.net/~elliemiller/index.html. If you can’t find the answer to your question there, try Bird Watcher’s Digest at 1-800-879-2478 or check out their FAQ at www.birdwatchersdigest.com.