Do Robins Reuse Their Nests?
By Linda Ewing
“A pair of robins nested near me. Will they be back next year?”
First and foremost, congratulations! Spotting a nest in your yard, or while walking in your neighborhood or a favorite park, testifies that you’re paying attention to the natural world. If you’ve seen one before, you might wonder: do robins reuse their nests or build a new one every year? Wanting to know more about the birds that built the nest is a great introduction to the complexity of bird nesting behavior.
The life cycle of an American Robin’s nest
The short answer to “do robins reuse their nests” is “not usually.” But it’s the long answer that’s more interesting.
Robins typically start each season by building a new nest rather than reusing an old one. Nest locations are chosen by the female in early spring. While a tree with forking branches and dense leaf cover would be her first choice, robins are nothing if not adaptable. They sometimes repurpose human-built structures, nesting in eaves, planters or on top of porch lights. In the Great Plains, they may nest in low bushes or even on the ground. In the mountains or along rocky coasts, they’ve been known to build their nests on cliffs.
The male, as part of his courtship behavior, gathers and delivers nesting materials. These may include mud, twigs, grass, moss and human debris - paper, ribbons and shreds of plastic bags often turn up in the nests of urban robins. His mate then transforms these offerings into a woven, cup-shaped structure, spackled with mud and lined with plant matter. A typical nest is 6-8 inches across, with an interior well roughly the size of a baseball. That makes a snug fit for the normal clutch of 3-5 pale blue eggs, laid a day at a time.
Even though robins’ eggs are laid over an extended period, the female does not begin to incubate them with her body heat until the clutch is almost complete. As a result, the eggs typically hatch at roughly the same time, 12-14 days after the last egg is laid. It can take the better part of a day for a hatchling-to-be to use the pointy projection on its bill – known as an “egg tooth” – to crack through its eggshell casing. When it finally emerges, the hatchling resembles an embryo more than a chick (the technical term for this is “alatricial”). Newly-hatched robins are naked except for a bit of fluff; almost translucent; blind; and generally helpless, dependent on their parents for warmth and regurgitated food. Within five days, though, the hatchlings’ eyes will open, their bodies will be covered with fluffy down, and their diet will shift to chunks of earthworms and other insects brought to the nest by their parents, who share care and feeding responsibilities. In another week, sporting new feathers, the chicks will be fledglings, ready to jump from the nest and begin to fend for themselves under the watchful eye of the male.
If it’s early enough in the season, the female will then begin to build another nest for a second (or third, or even fourth) brood. Why not reuse her existing nest? The answer is survival. Beyond general wear and tear, reusing a nest increases exposure to mites, ticks and other parasites and makes it more likely to draw attention from predators.
Nesting habits of other backyard birds
A quick survey shows just how diverse nests and nesting behavior are. The nests of Northern Cardinals are similar in many ways to those of American Robins: cup-shaped, tightly constructed, usually positioned in dense foliage and used just once. They’re more complexly layered, however, with soft plant matter over bark over leaves over twigs. Orioles are famous for their intricately woven, pendulous nests. Many other common backyard birds are cavity nesters, seeking out holes in trees, logs and human-made structures or, in some cases, excavating holes themselves. Starlings, bluebirds, wrens, chickadees and woodpeckers all fall into this category.
House Sparrows often nest in noisy colonies, stuffing dried grasses and other vegetation into any available opening, whether it’s a traffic light, a store sign, or the shutters or loose aluminum siding on your home. They are one of relatively few species that regularly reuse their nests. Mourning Doves are another, though an unkind observer might point out that their nests are so flimsy, it’s hard to tell.
How you can attract and support nesting birds
The best way to encourage birds to nest in your yard or neighborhood is to make it generally bird-friendly. Native plants produce the fruits and seeds, and attract the insects, that birds in your region have evolved to eat. Abundant food sources close at hand are especially important for breeding birds. So is water – just be sure to keep your bird baths clean. Dense shrubs and trees provide cover, as well as nest sites for open-cup nesters like robins and cardinals. Letting dead tree snags stand is a boon to cavity nesters like woodpeckers and wrens. Dried grasses and dead leaves serve as nest material, so leave them be as well. And if your trees or shrubs require pruning, wait until nesting season is over. That’s also when you should clean out any bird boxes you may have set up to attract cavity nesters.
As with all wildlife, “look but don’t touch” is the golden rule. This goes for the nests themselves, and it goes double for their occupants. Resist the urge to get too close, or to interfere with recent fledglings you may see on the ground. If you watch from a distance, you’ll be rewarded with a window into the fascinating world of breeding bird behavior.