A Feathered River Across the Sky

by Joel Greenberg

  Although there are records of passenger pigeons nesting in most of the states and provinces they regularly inhabited, many of these involved nesting as single pairs and in small groups, about which little is known. A report from Portage la Prairie, Manitoba, described the local status of nesting pigeons: “They do not in this locality build in colonies, but place their nests singly, usually in small oaks.” Unfortunately we will never know if those birds returned every year to form their little groups or whether in some subsequent year they joined the big nestings.38

  Charles Douglas, a bird student and nurseryman from Waukegan, Illinois, reminisced to a friend about his experiences with the few passenger pigeons that used to nest nearby: “All of the nests I found were in the same place each year, and in groups of three or four, not many rods apart, in the big pines near Lake [Michigan] and in a small hard-wood grove a mile west.” During the summer the birds entered his garden to eat cherries. Perhaps most noteworthy, the birds were allowed to nest and feed without disturbance.39

  At the northern part of their range, the birds would often begin arriving in March. Some who knew the birds believed that they liked to be on territory just before the snow disappeared, exposing the bonanza of the previous fall’s mast. Or they would scrounge bare patches of stream banks for worms. But just as many large nestings commenced when there was no snow at all.

  According to some observers, small groups would arrive, then shortly thereafter be joined by the multitudes. But synchrony was an important element, so the birds tended to appear en masse. Unique in the passenger pigeon record is the amazing account of Chief Pokagon, who found himself engulfed by a huge flight of eager pigeons. In May of 1850, he was trapping on the upper reaches of the Manistee River in Michigan:

  One morning on leaving my wigwam I was startled by hearing a gurgling, rumbling sound, as though an army of horses laden with sleigh bells was advancing through the deep forests towards me. As I listened more intently I concluded that instead of the tramping of horses it was distant thunder; and yet the morning was clear, calm and beautiful. Nearer and nearer came the strange comingling sounds of sleigh bells, mixed with the rumbling of an approaching storm. While I gazed in wonder and astonishment, I beheld moving towards me in an unbroken front millions of pigeons, the first I had seen that season. They passed like a cloud through the branches of the big trees, through the underbrush and over the ground … Statue-like I stood, half-concealed by cedar boughs. They fluttered all about me, lighting on my head and shoulders; gently I caught two in my hands and carefully concealed them under my blanket.

  I now began to realize they were mating, preparatory to nesting. It was an event which I had long hoped to witness; so I sat down and carefully watched their movements, amid the greatest tumult. I tried to understand their strange language, and why they all chatted in concert … The trees were still filled with them sitting in pairs in convenient crotches of the limbs, now and then gently fluttering their half-spread wings and uttering to their mates those strange, bell-like wooing notes which I had mistaken for the ringing of bells in the distance.40

  Almost all that is known about the actual mating of the passenger pigeon is based on Wallace Craig’s observations of the caged birds kept at the University of Chicago from 1896 to 1907. Attempts were made to crossbreed several of the species in this pigeon collection, including passenger pigeons. But passenger pigeons rarely mated with the other species as they acted rougher than ring-necked doves or rock pigeons. Either gender might initiate courtship. Sometimes the male passenger pigeon would land next to the female and press hard against her, often stretching his neck across hers in what the scientist called “hugging.” (Perhaps a better term might be necking.) Craig notes, “Male presses over on perch against female, gives keck twice without raising wings, then preens inside wing, a sign of eros.” She rebuffs his initial overtures, but eventually his subtle technique ignites her amorous spirit and she hugs him in return. Then, like all pigeons, they clasp bills, but in this species the contact is fleeting. She sits erect while he alights upon her back and clambers toward her neck, wings flapping all the while. Eventually she slumps, perhaps out of weariness, and lifts her wings to support him so that the act may be consummated. Upon separating, the male assumes “a position of fear,” perhaps anticipating what is next on her agenda. Feathers out and neck withdrawn, he “clucks in a soft toneless voice.” She replies in kind, before smacking him with her wings, another characteristic restricted to passenger pigeons. But she is just joshing, as their postures stiffen and they begin tickling each other for a few seconds.41

  Some said passenger pigeons were monogamous, even to the point of forsaking all subsequent breeding should they lose their mate. This is unlikely to have been the case, but there would have been no way to know even if it were true. Nest building and egg laying generally took around three days. The nests were simple affairs consisting of seventy to a hundred twigs seemingly dashed together into the shape of a shallow cup to hold the egg. Males collected the branches from the colony floor and from farther afield, but should they drop their cargo, they would rarely retrieve it, although another bird might. Indeed, after a while, the ground looked as if it had been swept. Many observers were struck by the apparent flimsiness of the nests, one even calling them “shiftless.” Some said that when standing directly underneath, it was possible to see the egg. Despite these poor impressions of the nests, however, the structures often persisted for years: the remains of some nests were still discernible up to twelve years after they were made.42

  Passenger pigeons manifested little fussiness in where they placed their nests, using the local features and trees to their best advantage. Zebulon Pike found islands in the Mississippi River between what would be Illinois and Iowa where the birds nested on small trees in such abundance that “the most fervid imagination cannot conceive their numbers.” In the Allegheny (New York spelling)/Allegany (Pennsylvania spelling) Mountains, the pigeons liked to nest on headwater streams, then spill downstream and up the wooded slopes as their numbers swelled. Several observers claimed the “nesting grounds were arranged with military precision.” The borders, mostly straight lines, were clearly demarked, even if it meant that a tree on the edge would have nests on the inside face but be empty on the outside. This was a function, though, less of design than the birds’ preference for a certain density. According to John French, arriving flocks would occupy their own wards, separated from others by “avenues … one mile or five miles wide” devoid of nests.43

  Hardwoods were the trees of choice for these Pennsylvania nests, but open-growth hemlock also hosted their share. In other places nesting colonies tended to be in wet areas. Central Ohio’s Bloody Run Swamp consisted of a low bog dominated by willow and poison sumac surrounding a higher middle where soft maples, swamp ashes, and white elms provided the nesting trees. The southernmost pigeon city on record formed along fifteen miles of the Tombigbee River in northern Mississippi. The mature forest consisted of such pigeon staples as oaks and beeches, as well as southern specialties such as sweet gums and cypresses. Different still was the great nesting north and east of Sparta, Wisconsin, in 1871. Most of these pigeons utilized a sandy area bristling with scrub oaks, but many birds spilled into more substantial timber of hemlocks and pines.

  Breeding pigeons crammed their nests into almost every available space. John Josselyn wrote of his trips to New England in 1633 and 1663 and described traveling miles through pine forests loaded with passenger pigeon nests. A beech tree in a New Hampshire nesting colony in 1741 allegedly supported five hundred nests, while a visitor emerging from the Sparta site talked of seeing large trees with as many as four hundred nests. These were exceptional, if not exaggerations, but claims of sixty to one hundred were frequent.44

  Dr. Gideon Lincecum is responsible for all that is known about the extraordinary Mississippi nesting. He and three companions rode horses into the swamp to check the progress after an eight-day absence: “Through all … the thir
ty square miles of that densely timbered bottom, from as high as one’s head on horseback on the saplings, to the topmost limbs on the tallest trees, not a vacant spot where a nest could be crowded in, was to be found anywhere. We all searched with that object in view. The foliage of the trees had not yet unfolded but the packed and muffled up appearance of their tops made the swamp dark as midsummer.”45

  It might seem that with all the hunters running around nesting colonies, the number of eggs that the species laid would be a settled issue. But many otherwise thoroughly credible accounts are wrong on this point. Audubon and others said that two eggs were the norm, while Wilson and his faction claimed one. The best evidence makes it clear that only one egg was laid per nest: this is based on all but one (and that one is suspect) of the reports on captive birds and from a majority of the observers. Some of those who claimed two eggs, and many of these who also said that the birds nested multiple times during the season (a much harder issue to resolve in the absence of scientific techniques), were pigeon hunters who wanted to downplay concerns that the bird was becoming depleted. Honest error could also have crept in because in the crowded, chaotic pigeon cities one hen could have laid in another’s nest.

  Many others fudge the controversy by saying that the pigeon usually laid one egg, but on occasion would lay two. But in almost all instances, those claiming firsthand knowledge say it is either one or two. An exception is the writer who said that where the food supply was far from the nesting location, only one egg was laid. This might make sense except that the well-fed captive birds always laid one. J. P. Giraud, an early ornithologist, claimed that two eggs were laid but the oldest chick would toss the younger one out of the nest.46

  My favorite account that attempts to shed light on this question cannot be reconciled even with itself. William Lehman visited the large 1870 nesting in McKean County, Pennsylvania, to obtain squabs (pigeon chicks) for his uncle. The uncle had created a spacious, well-watered, and vegetated park for the pigeons so that he might domesticate them. Lehman climbed small trees and in nearly every one claimed to have found two squabs per nest. He took fifty young birds, which he conveyed to his uncle. During their extended captivity, not one of these ever laid more than one egg per nesting.47

  Typical of all pigeon species, the hens and toms divided up their domestic duties during the period of incubation. At dawn all the adult males would leave the colony to forage for several hours. They would return in midday to relieve the hens, who would then take leave for their own feeding forays. By late afternoon they would reappear, and the males would make one last flight for food before they came back at dusk. Although almost certainly incorrect, a common, but not universal, belief was that the birds would not feed within the nesting grounds so as to leave forage for the squabs. There is also evidence that the toms would often roost outside, though close to, the nesting areas. It was thought that they did this to minimize the chances that their great numbers would damage nests.

  A passenger pigeon chick, or squab. Taken in Chicago by J.G. Hubbard in 1896 or 1898, this is the only known photo of a living passenger pigeon squab. The bird was one of those in Professor Whitman’s collection.

  Courtesy of Wisconsin Historical Society

  The literature is replete with stunning depictions of the comings and goings of hens and toms. A morning exodus of males caught one group of Wisconsin hunters by surprise. The men had entered a portion of the huge 1871 nesting before light to “rake” the males as they embarked on their morning feeding round. With the first slight signs of dawn, small flocks of pigeons began to stir: “And then arose a roar, compared with which all previous noises ever heard are but lullabies, and which caused more than one of the expectant and excited party to drop their guns, and seek shelter behind and beneath the nearest trees. The sound was condensed terror. Imagine a thousand threshing machines running under full headway, with an equal quota of railroad trains passing through covered bridges—imagine these massed into a single flock, and you possibly have a faint conception of the terrific roar following the monstrous black cloud of pigeons as they passed in rapid flight in the gray light of morning, a few feet before our faces.”48

  An egg took two weeks to hatch, and brooding birds would squat with their bodies centered over the egg. When intruders appeared, the adult would tilt to one side to take a more cryptic stance and to free one wing should it be necessary to strike out at the threat. To shelter the squabs once they hatched, the adults would often use one wing to hold the baby next to the body.49 A Detroit newspaper from 1880 describes a baby pigeon in these colorful, if unflattering, terms: “a featherless, hairy, misshaped, ugly looking little wretch of a bird, which soon develops the voice of a horse-fiddle in bad repair and the digestive capacity of half a dozen 14-year old boys.”50

  Squabs fed on pigeon milk, a curdy substance resembling loose rice pudding that originates in the crop of both the toms and hens. In pigeons the crop lining sloughs off to produce this highly nutritious milk that spurs rapid growth of the young. Analysis of this material shows that it is richer in protein and fat than human or cow’s milk. Later, the milk is mixed with adult food. The adults opened their mouths wide, and the young stuck their bills into the corners to feed. Should the milk-laden squabs fall (or get pushed by the myriad of hunters who sought them out), they would often splat on impact like rotten fruit.51

  It was widely reported that both hens and toms would feed orphans. To the extent that this behavior occurred, it was due either to confusion or because the accumulation of milk would be an irritant to the adult; at least one writer said that the failure to dispense with the substance could even prove fatal, although that seems incredible. That the orphaned squabs would be cared for was a favorite claim of the pigeon hunters, for it minimized the impact of the killings. It is indicative of their mind-set that Edward Martin, a game dealer dubbed Pigeon Butcher by author William Mershon, offered this story as evidence of his claim that adults would feed “squabs indiscriminately”: “I may mention that one of the men in my employ this year … in one afternoon shot and killed six hen pigeons that came to find the one squab in the same nest.” The field of public relations was evidently still in its infancy.52

  The adults would feed the young for about two weeks. Then there came a day when the adults, finished with nesting, would rise in a dense cloud and evacuate the colony, leaving behind the roly-poly squabs to fend for themselves. They must have been quite a sight, for the youngsters “wander around like drunken men for three or four days.” In the eyes of another, however, their movements were inexorable as they hiked their way to strength and flight: “If they came to a road they crossed it; a stream, they flew over; or they fell exhausted into the water and, flapping their wings, swam to the other shore and ran on until night.” After another few days, they, too, could take to the air and form flocks that joined the adults. It is likely that this abandonment was due to human disturbance and that few if any of the younger chicks survived.53

  Despite what would seem to be the overwhelming chaos of these mass nestings, the adults more often than not managed to return to their own nests. By what means they accomplished this amazing feat is not known. Yet another of the great questions that can never be answered regarding the life history of this species is how many times a year they bred. The literature provides a range of answers that is literally as great as it can possibly be: from once to monthly. One author said eleven, giving the birds a month off for travel. Without marking birds, no one could know for sure. Schorger concluded that they nested only once a year. This is based on his examination of the record and failure to find large nestings in the same year that were far enough apart in time for the same birds to be involved. He also points to the prodigious quantities of mast that would have had to be available in the same place to support two nestings in the same year. He does acknowledge one possible exception, and that was the Petoskey, Michigan, nesting of 1878, where birds did linger long enough to have nested twice. There are also rec
ords of single nests being found in August and September, but these may well have been second attempts after previous ones had failed or might have meant hatching-year birds were breeding for the first time. Some passenger pigeons might on occasion have had multiple broods in the same year, but it’s unlikely that many of them did so with any regularity.54

  MEMBERS OF AN ECOSYSTEM: RECONSTRUCTING THE PAST

  Thus it will be seen how the all-wise Creator, even in the case of these birds, has so wisely adapted the size of the food supply to the number of mouths to be fed.

  —PEHR KALM

  Billions of passenger pigeons moving across the Canadian and American landscapes were subject to the constraints imposed on all species. A number of known factors took their toll on birds, although the principal limitation was the forage base itself. As many birds as there were, the population could not exceed the capacity of their environment to sustain them. That environment, of course, held physical and biological forces that culled varying numbers of individuals.

  Adverse weather has always been the bane of migratory birds. (One of the worst kills on record occurred during the Memorial Day weekend of 1976, when a storm claimed over two hundred thousand warblers, thrushes, and blue jays that were later discovered covering a short section of Lake Huron shoreline.) Although as well suited as any other species to withstand the vagaries of atmospheric forces, passenger pigeons were not immune. In the spring of 1740, several sea captains related a calamity the likes of which they had never before seen. They had just reached Philadelphia, having traversed three miles of floating passenger pigeons. The prevailing speculation claimed that inclement weather had forced the birds offshore and prevented their return. Then the onset of night and weariness drove them to the water, where they perished. Less than a century later, Henry Schoolcraft found the beaches of Lake Michigan strewn with “great numbers of the skeletons and half-consumed bodies of the pigeon, which, in crossing the lake, is often overtaken by severe tempests, and compelled to alight upon the water and drowned in entire flocks.” Fog rather than wind proved most dangerous to passenger pigeons, particularly those experiencing their first migration, for the adults had the savvy to rise above the poor visibility into clear sky.55