Chapter 5: Cradles of Love

Hanging from one side of the robin’s nest are two fringed white satin badges, fastened by mud and sticks. They bear the seal of New York and the words, “New York N.E.A. at Boston, 1903.” We have found that these badges were worn at a national educational convention held in Boston. A little to the left of these badges, near the rim of the nest, is a knot of coarse white lace, not merely woven over and under the grass, but artistically coiled about the outside and securely fastened with mud and tiny sticks. Through this lace, woven in and out through its coarse mesh as neatly as any human being could do it, are two white chicken feathers. The rest of this remarkable nest is decorated with long pieces of string; white string, brown and yellow string, a piece of blue embroidery silk, the hem of a fine handkerchief and a bit of white satin ribbon. Turned upside down, the nest gives one the impression of a bonnet with satin strings and trimmed with a little knot of white lace and two white quills. A truly wonderful nest!

Robins build nests from Mexico to northern Canada, from the Atlantic to the Pacific coast, from sea level to 12,000 feet in altitude. This impressive distribution suggests that robins can successfully adapt to a wide range of different nesting environments. Since flexible acceptance of breeding conditions is an important aspect of an animal’s ability to withstand destructive pressures exerted against its population, the American Robin must in this regard be considered one of evolution’s best accomplishments.

Nesting involves selection of an appropriate site as well as actual construction of the nest itself, and for the robin, these two tasks entail separate sets of environmental requirements. What these requirements are and how they are negotiated make up one of the most interesting chapters in the robin’s life cycle.

Site Selection

Selection of the nesting site, a matter of considerable deliberation for most robins, is a chore primarily undertaken by the female. The male may occasionally offer a suggestion or two by bringing nest-building materials to a certain spot. But such recommendations will likely as not be declined by the finicky female. In one case like this, a Massachusetts male began repairing a previously used nest only to have his wishes adamantly ignored by his mate, who eventually chose a site some distance away. In picking the site, the female may appraise several possibilities by lowering herself onto each one as if testing for sufficient room. She may then betray a bit of indecision by beginning nest construction at two separate places before settling on her final choice.

This choice is generally some five to twenty feet above the ground, although sites on the ground itself or as high as sixty feet are sometimes used. Concealment does not appear to be a crucial requirement—indeed, robin nests are often among the easiest in birddom to locate—but a firm foundation is of paramount importance. The robin’s statant nest is supported primarily from below (in contrast to suspended nests which are supported from the rims or sides) and so is usually built upon a sturdy branch, fork or crotch of a tree. In this respect, old orchard and shade trees suit the Robin’s needs particularly well.

Concealment does play some role in site selection, of course. Robins, who rear two or three broods of young each season, usually employ separate nests for each brood. And largely due to considerations of concealment, the first nest—built in early spring when many deciduous trees are still leafless—is most frequently constructed among the branches of evergreens. For the season’s second brood, however, most females prefer the now-foliated (and thicker-limbed) deciduous trees for housing their nests.

Nesting Neighbors

Since robins defend their nesting territory against other robins, side-by-side nesting by two pairs of redbreasts almost never occurs. There are, however, many instances of robins congenially nesting with other species in the same tree, with two nests sometimes as little as a foot apart. Thus robins have been known to nest simultaneously with kingbirds, orioles and vireos, all in the same tree and all successful in rearing their young. As long as these different species do not heavily compete for identical food resources, such associations may not be significantly disadvantageous. Peculiar problems, though, can arise. Once in a Pennsylvanian evergreen grove, a Purple Grackle’s nest was found to contain not only two grackle eggs but a robin egg as well. Apparently, the robin who had built her nest in the same grove accidentally visited the wrong nest at the wrong time.

Another case of mix-up between avian neighbors involved some robins who had nested only nine feet from the homestead of a pair of kingbirds. The two species got along fine until a bird-banding ornithologist decided to approach the kings’ nestlings. Perceiving potential peril, the male robin perched near the menaced nest and began issuing vigorous warnings to the oncoming human. But instead of supporting the defense, the thankless Daddy Kingbird promptly pecked his neighbor’s noggin until the startled samaritan abandoned the altruistic affray. Presumably the robin had gotten too close to the king’s babies.

Some nesting neighbors can be more than mere nuisances. English Sparrows, diminutive in size but colossal in spirit, sometimes badger nesting robins until they move elsewhere to make their home. And Blue Jays, those egg-stealing archenemies of robins, almost never make welcome or even tolerated neighbors. Indeed, the two species usually fight whenever they meet. In one informative exception to this general rule, however, a pair of robins once nested in the same tree as a pair of jays. With at least one sentry always on guard at the nest, the cautious redbreasts eventually succeeded in fledging their young. But their cause was even more notably aided by a local outbreak of inchworms on which both bird families could readily feast. Very likely, such superabundancy of suppers not only reduced the robins’ tendency to drive the Blue Jays away, but at the same time decreased the jays’ motivation to rob robin nests.

Comparable increases in tolerance among normally antagonistic species frequently develop amid prey-a-plenty. Both hawks and owls, for example, uncharacteristically endure the presence of other raptors (both of their own species and of others as well) wherever runaway rodent populations arise. This process of antipathy reduction, which permits a greater density of predators to coexist within a given area, is one of Nature’s mechanisms for controlling local outbreaks by such prey species as rodents and inchworms.

Artificial Sites

While some robins nest deep in the forest, the majority build on the outskirts of woods and, as almost everyone has observed, in bushes and trees within human-inhabited areas. Often these sites are not merely near our constructions but actually upon them, sometimes causing considerable (though readily accepted) inconvenience to the landlords. Thus city construction has been halted while robin tenants nested on girders, telephone booths have been closed while robins raised young atop the dial box, house painters have been routed by irate and fretful bird parents, school children have been relegated to backdoor entrances while Mother Robin sat watch in front, and burly policemen have been reduced to whispering, goggle-eyed godfathers during the five-week period that nesting robins invaded headquarters. Robins have even gone so far as to nest, quite successfully, within the pocket of a coat left hanging on a garden tree by a forgetful musician.

Robins do not even insist that their nesting sites remain absolutely stationary. One mother-to-be in Ithaca, New York, reared four babies atop a steel crane which constantly swung back and forth to load cinders aboard railroad cars. “It must be like life on ocean waves,” a metaphorical crane operator remarked at the time. Another and even more incredible example of the robin’s acceptance of mobile homes was reported by the New York Times in 1946. According to the Times, a robin both constructed and egged a nest on a Chicago & Northwestern locomotive in Sioux City, Iowa. Even though the engine chugged here and there every once in a while, the unperturbed bird managed to accomplish her motherly chores by following the train throughout its meandering jaunts.

The robin’s ready acceptance of these unnatural nesting sites strengthens a point made earlier—namely, that robins show considerable adaptiveness in their tolerance of nesting conditions. An occasional individual, to be sure, may reveal marked inability to adjust to a particular environment, especially if that environment defies “natural” laws. Take for example the case of the robin who built her nest on the south end of a shed covering a turntable upon which the direction of a train locomotive could be reversed. When the south end of the shed was turned north, the unthinking bird simply built another nest on the “new” south end. Since the shed rotated periodically from day to day, the obliging robin soon had two nests and two sets of eggs, and at last accounts was incubating whichever nest happened to be facing south at the time. This poor female obviously lacked enough insight regarding the nature of her situation to successfully adapt. Yet were she not as adaptable as she in fact was, she would not have tried nesting in such a strange setting as a railroad yard in the first place.

This perky propensity of the robin for choosing nest sites near human constructions and activities is encouraged by four factors. First and foremost, during the breeding season robins are not nearly as timid as many other bird species, and are not easily frightened by humans. Nesting robins in fact make excellent subjects for nature photographers who are frequently permitted to take closeups that other species find intolerable.

Second and relatedly, many predators are not tolerant of proximity to people and thus robins obtain a degree of safety by nesting where predators fear to tread. In towns situated within America’s northern woodlands, deer calmly forage on lawns in complete safety from people-fearing wolves. In like manner, while that robin nest on your windowsill may be plainly visible to every crow in the area, most crows won’t approach close enough to do the robins’ eggs or nestlings harm.

A third factor underpinning the robin’s tendency to nest near humans is the abundance of robin-type food in cultivated areas. Worm-filled lawns, for example, are especially attractive to robins. And food is always a dominating concern of nesting songbirds since their babies consume enormous amounts as they grow toward independence.

Finally, many of our buildings, bridges, and fences provide nesting sites that offer ample support and hence appear ideal to the critical eye of a scouting female. Sometimes there is a cornucopia of excellent sites, whereupon Mrs. Robin may embark upon a veritable orgy of nest-building. Years ago in Ohio, construction workers watched a robin begin twenty-six separate nests in the spaces between a wooden girder and the roof rafters lying across it. After a week of self-indulgence among these irresistible sites—with workmen supplying building materials and placing bets on where the final functional nest would be—the female settled on one nest, laid eggs, and hatched them.

Unfortunately, such compulsive capers do not always conclude so well. Once a robin started nests on five separate fire-escape steps, completed two of them, laid two eggs in one nest and one egg in the other, spent five days incubating both sets, and finally abandoned the whole endeavor. Such behavior serves well to remind us that robins, like all creatures, sometimes display considerable individual variation in their actions. Two robins, faced with what appear to be essentially comparable situations (such as an abundance of attractive nesting sites), may respond in two completely different ways—one bird successfully settling on one site, the other abandoning all the sites in utter irresolution. Such individual differences can be extremely interesting. Yet they are not so satisfying to discover as are general principles or “laws” of robin behavior, since recognition of these laws adds to our appreciation of the underlying orderliness that generally characterizes Nature.

Nest Construction

In nest construction, as with site selection, the female assumes primary responsibility. The male frequently brings materials to the site and may even help build to some extent, but more likely he will only drop his load haphazardly on the side of the emerging structure. On the whole, his mate makes more material-gathering trips (perhaps more than a hundred in a twelve-hour period), brings bigger loads (sometimes so clumsily large that all but her flapping wings disappear from front view), and does by far most of the actual construction (all of it, in many cases). In those instances where the male does pitch in, however, he and his mate cooperate fairly closely, with one bird remaining at work on the nest until the partner returns with more building materials.

Robins usually take five or six days to build the nest for their first brood of the season, and then somewhat less (perhaps two or three days) for their second brood’s nest later in the summer. The exact amount of time that nest-building takes, though, varies considerably among individual robins, and the same bird—should her nest be destroyed as she is beginning to lay eggs—may build an entirely new nest within a single day. Like construction time, the size of the final product varies but generally measures six or seven inches across the top and three inches in height; the inside is about four inches wide and two-and-a-half inches deep.

Stages of Construction

The typical nest is built in three distinct stages. First, coarse grass, straw, leaves, rootlets, and occasionally pieces of paper or rags are formed into a firm foundation; slightly finer materials may be used to shape the sides. The robin greatly prefers that these materials be wet when she builds, perhaps because they are then more pliable. After the nest’s skeleton is erected, the female stands in its center and then circles, squats, and presses down with her wings until the nest is molded to the contour of her body.

The second stage of construction consists of an inner lining of mud that varies in thickness from an inch at the bottom to a quarter inch at the rim. In making this, the female brings pellets of mud in her bill, peppers them into the nest walls and—having done this many times—gets into the nest, rotates her body, thumps her feet and slaps her wings to beat the wet plaster into shape. Interestingly enough, robins have been known to use the castings of earthworms (subterranean dirt that has been eaten and then excreted on the surface) as mud for their nests, even when “regular” mud was abundantly available.

The third and final stage of nest construction usually begins before the mud layer is entirely hardened. As her final touch, the female carpets her creation with fine, soft grasses which, as the mud dries, are soon cemented into smoothed fixity. Her cradle, now complete, is ready for occupancy.

Although these three stages typify the nest-building of robins, exceptions to this general pattern are not entirely rare. Occasionally the mud layer is completely omitted; or the female may skip the soft lining almost as if she had run out of time before her eggs began to arrive. Robins also achieve a bit of variety over ordinary construction procedures through an extravagant choice of materials, as markedly exemplified in this chapter’s opening quote. Other revolutionary architects have used equally unlikely materials ranging from Christmas tree icicles to horse-hair. One female who was offered an abundant supply of cotton-cloth strips, ferried so darn much of the stuff to her nest that, in the words of an on-site observer, “the whole affair soon became an unmanageable mess and was eventually abandoned.”

The three nest-building stages may also be modified if the female merely repairs an old nest rather than building a new one from scratch. While robins don’t usually use ready-made nests, they do occasionally reoccupy the same nest for successive broods within a season. In rarer cases, they use the same nest year after year. One extraordinary female, for instance, enjoyed the same nest for six consecutive years, with two broods per year, adding a new layer of material to the skyscraper structure each time.

Several bits of evidence suggest that such repetitive use of previous nests may not necessarily reflect fondness for a particular nest but rather loyalty to the site where the structure lies. More than one robin has laid her eggs on a bare window ledge in the same spot where earlier stood her nest, which had been removed by someone for some reason or other. In a similar vein, robins frequently make repeated attempts to rebuild nests on a given site should the first nest be destroyed; in one instance, a female in Cambridge, Massachusetts, stubbornly constructed a total of five successive nests on a low-lying tree branch after a busybody human had removed each of the first four structures in hopes that Mrs. Robin would pick a new location less vulnerable to cats. Thirdly, nests on buildings seem to be reused more frequently than are nests in trees, probably because the former enjoy better support as well as more safety from squirrels, jays, crows and other nest-attackers.

In addition to reusing their own nests, robins occasionally reclaim old nests of other species (for example, catbirds), albeit only after modifying the structure to their personal satisfaction. Much more frequently, other birds rear families in secondhand robin nests. Mourning Doves in particular like to renovate robin nests of seasons past; in some areas, as many as 20 percent of the robin nests that remain intact over winter are used by doves the following spring. (Indicative of the sturdiness of robin tectonics, by the way, is the fact that almost half of all robin nests are reusable from one year to the next—perhaps the highest such percentage for any songbird.) Occasionally doves even try to pirate a nest that’s in current use, in which case the owners may either meekly submit and move somewhere else or staunchly defend what is rightfully theirs.

The Import of Moisture

Because robins prefer mud and other wet materials for their nests, their building efforts are influenced to a large extent by the presence and absence of moisture in their immediate environment. Under normal conditions, the female tends to restrict her construction to early hours when morning dew blankets the ground. Should a summer dry spell occur, she and her neighbors will hold back on building only to be thrown into a flurry of construction when the rains finally come. Sometimes if the drought is severe, she may begrudgingly concede to the forces of Nature and build without mud.

Alternatively, the female may respond with undaunted determination to build her nest in accordance with accepted robin tradition. One ingenious bird was observed to wet her feathers by birdbath immersions and then shake herself off on a nearby dusty road, thereby creating for herself what Mother Nature wouldn’t. Another female adopted a similar solution but chose to reverse the process—she scooped dirt into her mouth and then dipped her bill into water before continuing nestward. These examples may say something about the robin’s resourcefulness, but they also comment on the importance of moisture during nest erection.

Rain drops, though, are much like family relatives—they’re quite all right if they visit in small numbers but if they arrive en masse they tend to overstay their welcome rather quickly. If rain persists after the robin has completed her mud layer, she may delay lining her nest until the sun shines and permits the clay to harden. In localities where steady stretches of spring showers are not uncommon, the delays thus produced may cause a decrease in maternal productivity since robins adhere to a tight schedule of rearing two or even three broods a season and cannot afford to waste any time.

Rain, moreover, can have even worse effects. Copious downpours may wash away much of the nest’s mud and repeatedly force rebuilding efforts. Even after the nest is completed and stuffed with young, it remains vulnerable to inordinately heavy rains, particularly if it sits on an exposed branch. Too often intense thunderstorms have succeeded in softening a robin’s nest and then, tragically, down tumble babies, cradle and all.

In conclusion, we might note several practices—suggested by the robin’s nesting habits—by which you can encourage a pair of redbreasts to build in your own backyard. Following these hints won’t guarantee success since suitability for nest-building is not the only characteristic which makes a given locality attractive to robins. Food supply, for example, is also important. Nevertheless, the following suggestions are worth a try.

A pan of wet clay set out on the lawn is a godsend to a Robin who is just beginning work on the mud layer of her nest. Should the weather be at all dry, she will probably be quick to utilize this unexpected source of plaster. Robins also appreciate string, cotton and other building materials that are made available to them. Pieces of string or yarn, though, should not be more than a foot long. Imprudent robins have been known to wrap themselves up with string, thereby becoming trapped in a mess that is either fatal or, as the following newspaper article describes, just plain embarrassing:

Fireman Frees Tangled Robin

Waukegan, Ill. (AP) — A high-strung Robin got the Waukegan Fire Department out at dawn today to save his neck. In search of home-building materials, he lit on a fine long piece of string but got himself all tangled up in it. Sam Gordon, a Waukegan merchant, called the Fire Department and a fireman on a ladder truck set the bird free.

Rumor has it that when this poor fellow finally returned to his nest, his blushing face turned as crimson as his breast and his mate—apparently mistaking him for a flirting cardinal—indignantly chased him away.

In addition to providing materials, you can create a good nesting site in your yard by erecting a sturdy shelf some five to twenty feet from the ground, preferably beneath a branch or other structure that will afford protection from heavy rains and summer sun. Since robins are not hole-nesters and would not use a closed birdhouse, the support shelf should be open on at least three sides. A piece of wood six inches wide and eight inches long, perforated with several small drain holes, will be certain to gain Mrs. Robin’s grateful approval.