Chapter 11: Change of Life

Most of us know the American Robin only in its breeding season—that quarter or third of the year when it compromises with its natural wildness and, like city squirrels and pigeons, accepts a measure of domesticity, nesting against our houses and getting its living from our lawns and gardens. It shows its adaptiveness in this because as soon as it is released from family responsibilities, it returns to the kind of woodland life it must have led before man came to America. In late summer, fall, and winter the robins live in loose flocks within the borders of woods and fly from a person in alarm before he has got close enough to discover their presence. It is hard to understand such wild mistrust of man among birds that have recently sought the shelter of his habitation for their nesting.

One fundamental principle of Robinology is that the birds never seem to be friendly toward both humans and other redbreasts at the same time. While at their nighttime summer roosts, for example, robins are relatively affable toward each other and yet nervously suspicious of people. Such sentiments are in sharp contrast with their daytime affections throughout the breeding season, for the then-territorial robins are hostile toward their fellows but show remarkable tolerance–sometimes downright chumminess–toward humans. Indeed, backyard redbreasts can sometimes be coaxed into accepting tidbits from the hand, and in one case a robin habitually followed a man about the neighborhood, without any food inducement whatsoever, so long as the gentleman “talked to it in a low, confidential tone” (Forbush, 1929).

As noted by Halle, however, this friendliness toward people dies with autumn’s fading leaves. By September, robins have not only begun flocking in apparent enjoyment of each other’s company, but are also beginning to flee from humans with all the timidity of skittish mountain sheep. It is at this season that a person can walk quietly into a wooded area which hides hundreds of robins, only to “hear a rustling in the foliage, a soft ‘whut-whut,’ and all vanish unseen” (Bent, 1949). Fall, then, marks a temperamental change of life for the American Robin, a time when humans become feared rather than trusted, a time when fellow redbreasts become comrades rather than adversaries.

The robin’s diet reflects a second change that ensues with the coming of autumn. All spring and most of summer, the birds feast upon the wealth of invertebrate life that abounds everywhere. By mid-fall, however, worms have retired far underground and most insects have either died or are hibernating in cloistered retreat. Forced to find other foodfare, robins turn to the abundant wild berries that now burst forth in ripened glory. Thus, at summer’s end robins shift from an animal menu to a vegetative one.

Yet another change is that of apparel, for fall is also a time for molting. To the year’s youngsters, molting means a loss of speckled vests and the donning of adult garb; for the adults themselves, molting means a change from bright breeding outfits to more subdued attire (duller breasts). During the short period necessary for these transformations, robins retire to sheltered wooded areas where they can doze, preen and eat in sluggish, solitary silence. Their sociable spirits reappear with their new suits, however, and soon the birds return to their flocks. The rest of autumn is then spent wandering from one berry patch to another as the birds build up fat reserves in anticipation of the impending journey south. Thus fall marks still another change of life for the robin, namely, the shift from sedentary breeding existence to more nomadic ways. Let us now turn to the highlight of this nomadism–the fall migration.

Fall Migration

Lacking the promissory air of the springtime trek, fall migration instead smacks of self-fulfillment, the aftereffects of difficult tasks now laid behind. In numbers swollen with youngsters, mutually congratulatory robins parade southward in a cheery epilogue to their prolific propagative achievements.

As was characteristic of the spring trip, fall migration is a most discontinuous event. Much of this discontinuity arises from regional variations in temperature (since warmspells induce northward retracings) as well as in food supplies (since local abundancies stall the migration, while scarcities hasten it). Though normally traveling at such modest rates as twenty to thirty miles daily, robins may scramble one hundred fifty miles in a single day if, having been lulled behind schedule by cozy temperatures or abundant berries, they suddenly get nipped in their posteriors by a scolding Jack Frost.

Although, loosely speaking, robins fly south in the fall, they do not actually follow a strictly southern course most of the time. Birds who are migrating in the eastern portion of the continent, for example, fly in a decidedly southwesterly direction — and with good reason, since a purely southward flight would carry them out over the Atlantic Ocean. (This is not to say that robins simply follow the coastline since birds who are well inland pursue a southwesterly direction too.) In complementary fashion, robins in the western part of the continent tend, with some exception, to follow southeasterly courses.

Where exactly in the South do migrating robins go? The vast majority–some 80 percent–fly to the Gulf states, and many of the remaining birds go to the coastal areas between North Carolina and Florida where the ocean acts to moderate winter weather. A small percentage may go into Mexico — robins have been found as far south as Pachuca, Hildalgo, which is about seven hundred miles below San Antonio, Texas–but most redbreasts remain in the United States. Mexico, no doubt, is usually too warm for robins who seem to prefer winter temperatures between 40°F and 60°F.

In any event, the specific southern region to which a given robin migrates depends in part upon the longitudinal location of that bird’s breeding grounds. Most robins who summered in eastern North America migrate to the region lying between Florida and Louisiana; those who summered in the Far West generally head for the Texas-to-Louisiana region; and those who bred in the central part of the continent may end up anywhere from Florida to Texas. In other words, although there is a wide range of potential wintering homes for any given group of robins, no westerners vacation in Florida and no easterners fly to Texas.

Surprisingly, not all robins within a given breeding locality migrate to the same place. To borrow an example provided by one ornithologist, one robin from Chicago may head to Miami while his next-door neighbor flies instead to Houston. Thus, rather than all robins from a given area migrating together to a specific southern resort, the birds instead migrate “in a random manner so that robins that summered in a given locality scatter widely in the Winter” (Speirs, 1946). Robins still migrate in flocks, of course, but each flock may contain representatives of many different breeding localities rather than just one.

One striking aspect of fall migration–a characteristic which is not shared by the springtime journey–is the great degree to which humans care about the robin’s ability to make the trip. Should a robin become injured while staying in the South and for that reason be unable to fly back to northern breeding grounds in the spring, no one is likely to give the problem much thought. But let a robin be unable to fly south in the fall so that the bird is seemingly at winter’s mercy, and he or she will be whisked off to Florida like some foreign dignitary on a matter of utmost importance. One male robin, for example, was felled by a stone just as winter arrived at Racine, Wisconsin. This poor fellow was half-frozen when rescued by the Racine police who patiently nursed him back to health. Headache gone and blood de-iced, the reprieved redbreast was then rushed to Jacksonville, Florida, aboard a southbound train.

Then there was the case of “Joe,” a robin who was stranded in chilly upstate New York (Malone, to be exact) after being grounded by an untimely cat-attack. Suffering from a broken wing, Joe wisely let himself be captured by a sweethearted florist who paid a special bird-rate of $6.63 for a one-way plane ticket to Miami. More than three hundred people gathered to wish Joe bon voyage as he began his first-class Eastern Airlines flight to the sunshine state. Smug with the knowledge that he had just set a tough-to-beat robin record for the fastest migration time, Joe quickly recovered from his injury and was soon released to bask in palm trees and romp in the surf. Presumably, Joe flew the thirteen-hundred-mile return trip under his own power the following spring.

Implicit in such anecdotes is the presumption that migration comprises a difficult journey that is manageable only by the fully fit. No doubt migration is indeed a hardship, for many birds die along the way. Yet through fate or providence, some blatantly handicapped misfits occasionally manage to negotiate the long trip quite successfully. One such miracle involved a male whose body was pierced by a stick which

appeared to enter the back at the left of the backbone and behind the heart and the lungs, penetrating the body in the area of the stomach and kidneys, but just enough to one side to miss them. … About two inches of the stick projected from the back of the bird, and about an inch protruded from the breast.

In 1941, this sorrily shish-kabobbed soul–presumably the victim of some accidental impalement–mated and reared two broods of young in Saddle River, New Jersey. He then disappeared for two years but reappeared in 1943 on the same lawn as before, still sporting the unwieldy stick. Conceivably this plucky bird was among the handful of robins who, as we’re about to see, remain north in the winter; much more likely, however, he not only migrated south with fellow redbreasts but made the round trip twice to boot.

Winter

Although the majority of north-breeding robins migrate south in the fall, a significant minority inevitably chooses to defy winter’s icy onslaughts by remaining far above the Mason-Dixon line. Before we consider the birds that do migrate, let’s first take a look at the nonconformists–those Winter Robins of the North.

Winter Robins

Robins of both sexes can be found throughout winter in regions as far north as upper Newfoundland and British Columbia. Since these birds are usually both few in number and hidden within heavily wooded areas, they are seldom noticed by people. However, one winter in downtown Ottawa, Ontario, several robins “took up headquarters in trees around Parliament, where their well-known call notes greeted passersby and made them wonder whether the seasons had suddenly been shifted” (Eifrig, 1910).

One popular explanation of Winter Robins holds that the birds actually migrate from breeding grounds that are farther north than their winter locations. Winter Robins in New England, for example, are commonly presumed to be native Newfoundlanders who migrated only as far south as New England before prematurely settling down. Winter Robins in New Jersey, meanwhile, are presumed to be birds who had bred in New England, and so on. In other words, Winter Robins are often thought to represent a process of mini-migration whereby the summer residents of a given locality are replaced by birds from areas farther north. This mini-migration theory usually presupposes that robins who breed in the Far North are “hardier” than those who summer at lower latitudes. Thus Canadian robins are often believed to be more vigorous and cold-resistant than New England robins, and that is the supposed reason why the Canadians are able to withstand New England winters while the New Englanders move to the milder South.

As plausible as this theory sounds, mini-migration seems to account for only a small minority of Winter Robins. Instead, the majority are in fact the same birds who bred at the localities wherein they now winter (thus Winter Robins in New England are not usually summer residents of Canada but are native New Englanders). There is, furthermore, no reason to think that northern robins are inherently more hardy than any of their southern relatives. Unfortunately, at present there seems to be no satisfactory explanation of why some robins ignore, or fail to possess, normal impulses to migrate south in the fall.

Regardless of their origins, Winter Robins face numerous problems of survival, the foremost being sufficient food. Naturally, adequate shelter from the biting wind is also important but satisfactory cover can usually be obtained fairly readily from evergreen groves and thicketed swamps. Warmth, in and of itself, comprises a less essential need since robins seem quite able to cope with extremely low temperatures so long as they are well fed; indeed, in some Canadian regions, robins have displayed no distress nor discomfort despite refrigeratory temperatures as low as 30° or 40° below zero. Food, not warmth, is the sine qua non of robin survival in the wintery north.

Freezing temperatures, of course, can render once-juicy berries into unpalatably petrified pebbles. Nevertheless Winter Robins cannot afford to be finicky and the birds generally eat anything they can find. The berries of sumac and mountain ash are common mainstays in the North, but nearly any fruit–including such autumn leftovers as frozen apples and pears–is patiently chiseled away. Sometimes the birds can supplement their impoverished diet with tasty worms during rare midwinter warm spells or, perhaps, near a bubbly hot spring that thaws the surrounding ground. Robins who winter near the coast can even occasionally add seafood to their diets; in one account, redbreasts near Godbout, Quebec, gathered on the low-tide shores of the St. Lawrence to scavenge such fare as whelks and seaweed amid broken chunks of ice. Despite all of these chance sources of nutrition, though, food in the wintery North is seldom reliable or extensive enough to support robins in any great number. Only as individuals scattered here and there can the birds find sufficient provisions to last until the affluence of spring returns.

Even when a single robin has an entire berry patch to itself, starvation may nevertheless threaten long before winter has run its course. Indeed, an attractive fruit-patch found in the fall may in fact prove lethal by luring a redbreast away from migratory inclinations. Once cold weather has arrived, the robin will be largely committed to remaining at the fruit-patch because scouting for food in the relative barren of surrounding areas would require more energy than the bird can now afford on winter rations. Even if the fruit-patch later becomes dangerously depleted, the robin will probably stay there because the patch

is still likely the best spot within the reduced explorable area available to the robin, with its reduced energy resources. As the days get shorter and colder, more and more of the bird’s energy is used up merely staying warm and alive, so less and less will be available for the luxury of exploring. Thus the food patch may act as a trap for southbound robins, and if the supply is not large enough to last through the winter, it may be a fatal trap.

Once robins have become significantly undernourished, their demise can occur in any number of unpleasant ways. Numbed by cold and weakened with hunger, they may slowly succumb to the elements if not to outright starvation; alternatively, the sluggish birds may perish more quickly under the slashing talons of a swooping owl or the crunching jaws of a pouncing cat.

Importantly, the fact that those robins who do have sufficient food are able to endure northern winters implies that the southward exodus of the general population is necessitated by lack of food in the bleak North and not by lack of warmth. This in turn suggests more generally that the migratory habits of a given species (such as robins) do not necessarily reflect climatic frailty compared to nonmigratory species (such as mockingbirds) which hold year-round residence in the North. It is probably the ability to find food during winter–rather than the ability to withstand cold–that usually separates migratory from nonmigratory species.

What can you do to help the Winter Robins in your locality? Not being seed-eaters and seldom accepting suet, robins will not profit from the foodfare that people usually offer birds in winter, although redbreasts will eat bread crumbs occasionally. Blueberries, raisins, olives and other small fruit as well as slices of apple are sometimes accepted with heart-warmed thanks. Redbreasts will also occasionally eat cottage cheese, corn biscuits and sometimes even cooked spaghetti. Dried mealworms are likely to be relished by robins as well as bluebirds, mockingbirds and starlings. For the robin in particular, all of these items may be more readily accepted if placed on the ground or a platform feeder rather than in a more typical bird feeder.

Robins in the South

While Winter Robins are fighting cold and hunger in the North, most of their kinsmen are enjoying relatively mild and bounteous conditions in the South. Initially feasting within berry-laden woodlands, the birds eventually strip every tree and bush of its fruit and so shift in late winter to parks, fields and similar areas to hunt ground-living insects. Throughout their stay in the South, robins retain much the same personality they displayed during fall: They are wary of people, they are non-territorial, they gather in great flocks, and they wander about the countryside almost continuously.

Years ago, the extreme shyness of robins was intensified by bird-hunting southerners who, for reasons discussed earlier, relished redbreasts more with their palates than with their hearts. As recently as the 1920s, such killing–although by then illegal–still persisted in certain areas. Relating this situation to the robin’s wintery shyness, one writer from Biloxi, Mississippi, remarked:

The robin here is by no means the bird of lawns and garden as in the north in summer, but is as wild as the wildest and frequents only remote districts for feeding and roosting here in winter. Perhaps the fact that Robin-Pie is still considered a delicacy by Negroes and “poor whites” is partly responsible for this condition.

Even though nowadays robins are no longer hunted, they remain shy creatures in winter, for shyness is part and parcel of their non-breeding personality.

The flocks that robins form in winter are usually quite large, often numbering fifty thousand or more; one aggregation of Western Robins in Oakland, California, was estimated at one hundred sixty-five thousand birds, and even larger flocks are sometimes reported. In those localities where they happen to congregate, robins virtually dominate the countryside, as indicated in the following report from Hancock County, Mississippi:

Over great tracts of young pine, cleared land, and burnt forest, we often walked, seeing hardly any birds but these [robins]. They flushed before us at almost every step and soon became an important feature of the landscape.

Robins so utterly ubiquitous that they flush “at almost every step’? Surely such a thought strains the imagination of us northerners who are so accustomed to seeing redbreasts scattered in mere two’s and three’s about our lawns.

The robin’s great flocks–so impressive in size–are all the more striking when they are on the move, which often they are. Some of their incessant wandering is prompted by food, and more particularly the availability of such berries as palmetto, hackberry, sour gum, holly, chinaberry, cedarberries, hawthorne, and mistletoe–for the simple reason that the robin’s huge flocks will soon deplete a fruit-patch of almost any size. Thus the birds move largely in quest of continuing sustenance.

Temperature, however, also guides the winter wanderings of redbreasts, and does so in much the same way as during fall migration. One researcher who studied the winter movements of robins in the South found that

during periods when temperatures were falling sharply or were continually cold, the trend of the movements [of Robins] was southward; when the temperatures were rising sharply and were continuously warm, the trend of the movements was northward. In other words, the Robins continued to move during the Winter in much the same manner as during the Autumn, except that during the Autumn, periods of falling temperature predominated so that there was a final resultant shift to the south.

Thus it appears that at least so far as the effects of temperature are concerned, the winter movements of robins are fundamentally similar to the birds’ movements during fall migration. As you will recall, redbreasts move precisely the same way during spring migration as well (they head northward during warm weather and southward during cold). In short, the fall, winter and spring movements of robins do not represent discrete phases in the species’ life cycle, but rather reflect a single response pattern to changing thermo-stimulation.

The winter wanderings of flocking robins frequently result in sudden, massive invasions of southern districts which only a short while earlier had been completely devoid of the birds. Occasionally robins even march into urban areas, especially if these happen to be rich in foodstuff. For days or even weeks, ten thousand robins may occupy a city before finally departing just as suddenly as they had arrived and leaving the town robinless once more.

For all their great mobility, however, robins may become entrapped by a snowstorm even in the Deep South during unusually severe winters. If harsh enough, these storms can kill, not through cold but by putting all food supplies under wraps. Many years ago, an especially bad storm in St. Petersburg, Florida, killed robins by the thousands. Although city residents tried to feed the birds soaked bread,

there was such a shortage of food generally that [people] swept up and hauled out truckloads of dead robins from the parks and streets of St. Petersburg. Upon dissection, they were found to be empty of all signs of food, literally starved to death.

Like an army amassed within a small space, the robin population is most vulnerable to wholesale destruction during those winter months when the bulk of its members are stationed within the relatively limited area of the Gulf states. And like an overpowering enemy that in one great stroke deals a crippling blow to its opponent, a single winter storm may inflict so many casualties upon robins in the South that their ranks will be noticeably thinned throughout the year to come.