A Feathered River Across the Sky
Page 2
FUELING THE FORCE: WHAT PASSENGER PIGEONS ATE
Passenger pigeons fed on lots of things, including earthworms, snails, locusts, ants, and various insect larvae. But seeds and fruits made up a vast majority of their diet. When Pehr Kalm, the only student of the great Swedish taxonomist Carl Linnaeus to visit North America, traveled from New York to Canada in the summer of 1749, he “cut up some of the Pigeons which the French had shot” and discovered their crops to be filled with the fruit of the American elm. In 1924, a female passenger pigeon that had been killed many years before had a full crop that held twenty-five samaras of the sugar maple (Acer saccharum), all of which had the extensions detached at their base.14
A couple of incidents illustrate how eagerly passenger pigeons sought soft fruit. When a huge cohort of young pigeons left their nursery in a Mississippi swamp, they dispersed into nearby strawberry fields to feed. Local Indians explained their feelings on the matter: “You eat up our strawberries, we will eat you, Mr. Pigeon.”15
Cherries drew the pigeons in this account by Henry Leonard. One summer day around 1870, two thousand people, many in bright costumes, gathered in Pigeon Cove, Massachusetts, to hear the Civil War general Benjamin Butler discourse on current politics. The speaker delivered his address from the shade of a large cherry tree, whose crown, adorned with ripe fruit, was visited daily by passenger pigeons: “In the usual afternoon feeding time of these birds a large flock of them alighted in every part of the tree; and although evidently surprised to find so great a company of men and women on the ground beneath them, and to hear the general’s husky voice sending forth sentences like rattling shot, they made no haste to fly away.”16
At least forty-two genera of wild plants were eaten, along with such domestic crops as buckwheat (their favorite), wheat, corn, rye, and hemp. Some of these became so thought of as pigeon food that their colloquial names reflected the connection. Margaret Mitchell searched the Canadian literature and compiled a list of seventeen such species including pigeon grass (Setaria glauca, S. viridis, and the nonnative Verbena officinalis), pigeonberry (Rubus triflorus, Phytolacca decandra, and Aralia hispida), pigeon cherry (Prunus pensylvanica), pigeon plum (Mitchella repens), pigeonweed (Lithosperma repens), and pigeon grape (Vitis aestivalis).17
When they had a choice, though, the birds overwhelmingly preferred hard mast, the forest nuts that vary in abundance from place to place and year to year. Although the birds would eat chestnuts, they were especially fond of beechnuts and acorns. (Even though chestnuts were a major component of many eastern forests, the historical record suggests that these trees played a small role in the life of passenger pigeons.) It is probable that a diet of these nutritious fruits during the time of breeding contributed significantly to reproductive success.
Each nut-producing tree has its own cycle. Beech, for example, produce heavy seed crops every two to eight years, making it one of the most variable of mast-producing trees in the forests of eastern North America. Despite this variability, large populations of beech seem to have masted every odd year throughout the 1870s at various places in Michigan, New York, and Pennsylvania. It was widely held that if the pigeons could choose a nut, they would opt for beechnuts, which are richer in nutrients than acorns.18
White oaks are also notoriously variable with good production every three to ten years, while black oaks are apt to mast at two- to three-year intervals. These cycles are based in genetics: large mast production insures that seed predators will be overwhelmed and some seeds will germinate; in low-mast years virtually all acorns are consumed. But they are also affected by both the amount of carbohydrates in the roots and the weather (a late frost could damage flowers and reduce the production of nuts in the fall).19
The acorns of some oaks, such as the white, mature in one year, dropping in the fall and likely sprouting by spring. Once sprouted, the nut retains little of its food value and ceases to be of much interest to the pigeons. Other oaks, such as the black and Hill’s, need an extra year to develop and would thus remain suitable forage for a longer period including the critical spring nesting season. Roughly twenty species of oaks shared territory with passenger pigeons, and the birds likely fed on the acorns of all of them to a greater or lesser extent.20
“It is a wonder how pigeons can swallow acorns whole,” wrote a perplexed Henry David Thoreau in his diary entry of September 13, 1859, “but they do.” Millions of years of evolution led them to that capacity through the development of elastic and capacious mouths and throats. A mouth with a breadth of just over one quarter of an inch could be almost tripled due to a joint at each corner of the lower bill. After ingestion, up to a quarter of a pint of foodstuffs could be stored in the crop, a pocketlike area off the esophagus. At such times, the bulging neck almost doubled the size of the body. (When such a bird was shot, “it struck the ground with a rattle like a bag of marbles.”) Eventually the material would be swallowed and then digested, taking up to twelve hours or more depending on what it was.21
A question that has survived beyond the pigeons themselves is how they knew where the mast was from year to year. Would the wintering flocks head toward the beech forests of Potter County, Pennsylvania, or the black oaks of Sparta, Wisconsin? Maybe this year it would be spring in the mixed woods of Benzie County, Michigan? It was thought by many in the nineteenth century that exploratory flocks of scouts would be sent out ahead to locate the choice areas and then return with the hordes. Simon Pokagon, a Pottawatomi chief and passenger pigeon historian (see chapter 3), broached the idea that passenger pigeons and other animals can communicate to each other over long distances. He suggested that something electrical in nature was involved.22
It is well-known that birds will suddenly appear at a newly present food source. In the tropics, the fruiting of a fig tree or the seeding of bamboo will draw an array of birds. A downpour in a parched landscape may well animate long-dormant invertebrates and even amphibians, which in turn quickly attract various birds. In North America, red crossbills are nomads that seek out the seeds of particular species of pine. Craig Benkman at the University of Wyoming has studied crossbills for years and believes that memory is a key piece of the puzzle in explaining how these kinds of birds operate. “I imagine that pigeon movements between areas of good mast were related to some knowledge of the distribution of the different mast trees and some recollection of current and past mast years,” he explains. “If there was a poor crop in one region one year, they would more likely return to that area than, say, another area that just had a good mast year.”23
The birds were also able to add to their knowledge. Crisscrossing almost a billion acres of range, the huge flocks of pigeons, possessed of superlative eyesight and often flying low, would be well equipped to assess the forage potential of vast areas. They would likely be able to remember at least to some extent what they had observed in the fall as a guide to their destination in the spring. Facilitating their search, mast areas tended to be extensive and so were easily located and able to accommodate lots of pigeons. This became a more serious problem for the birds as human activities whittled away at the forests, making it less certain that they would encounter areas of mast, at the same time that their populations were also decreasing. Yes, there would be fewer mouths to feed, but also fewer eyes to see. But each group of birds was not solely reliant on its own efforts: their knowledge of conditions would be augmented by the other flocks they met. “I suspect that a pigeon would be making a good decision to fly in the same direction that many other pigeons are moving in,” says Benkman. “This would also explain the increase in and massive size of flocks.” Vultures, wood pigeons, and great blue herons take cues from their neighbors in their selection of feeding sites. The ability to exchange information between individuals may be one of the reasons that some species form “large communal roosts.”24
Passenger pigeons fed in a number of ways. While furiously beating their wings for balance, they would stretch their bodies from the branch on which they
perched to pluck nuts within reach. This behavior led some early observers to surmise that the birds were dislodging the nuts with their wings, a behavior far too hazardous for any bird to undertake. A more spectacular sight ensued when large flocks descended to feed on acres of ground. As the mass of birds worked the area, there would be a constant leapfrogging, with the birds in the rear flying to the front to ensure they would receive their share. The birds moved in such a smooth and flowing manner they seemed to take on a fluidity that reminded some of water: “If they were approaching, there would be the appearance of a blue wave four or five feet high rolling toward you … When startled, their sudden flight would sound like rumbling thunder.” Another likened the spectacle to “a rolling cylinder … its interior filled with flying leaves and grass.” The scattering bits of vegetation made a “queer noise,” not unlike the wind rustling dry foliage. It was a testament to the fecundity of these forests that despite the quantity of nuts consumed by the pigeons, the very ground they had methodically worked often yielded seedlings in the spring.25
A SCENE OF CONFUSION AND DESTRUCTION TOO STRANGE TO DESCRIBE: ROOSTING
To nest or to roost, passenger pigeons gathered in colonies of varying size. Accounts often make it difficult to know if the pigeon congregations were for nesting or roosting. If the goal was to nest, the birds needed woods and foraging territory that could sustain them between four and five weeks. Otherwise, the length of their stay was highly variable, depending on such things as the number of birds, the quantity of food that was available, and the intensity of human harassment. Some of these roosts would be used repeatedly, as for example one in Scott County, Indiana, that was visited for seventy-five years. More often than not they were situated in low, wet woods. The roosts might occupy as little as six acres or be as vast as 120 square miles or more. Free of the constraints imposed by nesting, the roosting birds could leave at first light and not return until nightfall or even later, often traveling in excess of a hundred miles a day. A report from Tennessee said that to procure the nearest beechnuts, the birds made a round-trip of four hundred miles a day.26
Pigeons jammed themselves into the larger roosts at densities that are difficult to imagine. Sixteen-year-old Sullivan Cook ventured into the Lodi Swamp of northern Ohio for his first pigeon hunt around 1845. He and his brother started their adventure early in the evening and began hearing the birds from three miles away. Pigeons began flushing as they entered the swamp, but they held their fire until they reached the main collection of birds: “As we approached this vast body of birds, which bent the alders flat to the ground, we could see every now and then ahead of us a small pyramid which looked like a haystack in the darkness, and as we approached what appeared to be this haystack, the frightened birds would fly from the bended alders … We now found these apparent haystacks were only small elms or willows completely loaded down with live birds.”27
The largest roost known in Maryland was used from at least 1862 to 1872. Located in Allegany County, the site claimed six acres of alder swamp and was thought to draw birds from as far as fifty miles away. The place was packed: “So great was the number of birds that they were piled upon each other, in places, from one to two feet in depth.”28
Perhaps even more impressive than the sight of the birds at roost was the late-afternoon flight when the pigeons returned en masse. C. W. Webber writes about an autumn gathering in southern Kentucky, close to where his father lived. He began his vigil an hour before sunset. A few small groups of pigeons appeared and disappeared, presaging a silence profound and eerie: “Everything seems to wait—listening for the great coming.” A hawk and scattered crows, the latter flying without sound, headed toward the direction of the roost.29
The horses reacted first, pricking their ears at a newly discernible sound: “Is it a tornado coming? What a deep veiled roar! … The full burst of the deafening volume of that vast sound is borne upon you overwhelmingly with a current of fresh air strong enough to swerve you in the saddle. They are over us! We pause in speechless amazement. Half the sky is obscured … When will it cease? Is it one of the everlasting floods? We gaze until the real night is gathering around us.”30
Texas was on the southern periphery of passenger pigeon range. In the fall of 1881, however, the state saw a massive incursion of these birds, probably from the big nesting that year in Pottawatomie County, Oklahoma. This was both the largest and the last of such flights to reach southern Texas. A study of these birds also provides a rare glimpse into the movements of one pigeon population as it shifted its roost from place to place.
By October 1881, the birds had formed a huge roost on the Colorado River near Austin. When the acorns ran out, they split into two groups, each going in a different direction along the river. The flock that headed upstream settled in shin-oak thickets near Burnet. Merciless persecution by hunters dogged the birds during their entire stay, but the abundance of acorns kept them in place from mid-November through December. Regarding the acorn supply, one commentator quipped that they were “as thick as hops on a vine or ticks on a neglected cow.”31
The other flock roosted near Bastrop, just east of Austin. Here, too, they were killed by the thousands, but they stayed for only ten or twelve days before taking residence at Floresville in Wilson County, a bit to the south. The San Antonio Daily News of December 3, 1881, told this story of the roost with a straight face, although the second of the two alleged events is tough to swallow: “One citizen is reported to have killed 475 with a single stick, and another, while riding along with an overcoat on his back with large pockets, is said to have come out at the end of a lane with about three dozen of them in his pockets.” By the end of the month, the birds were on the move again and joined their former flock mates, who by now had vacated Burnet. It is likely that these flocks and others came together in a gargantuan roost in Real County that remained intact until early February. This time they picked a relatively safe place, for the site was Frio Canyon, an area remote from human concentrations.32
Although differing from one another in many respects, these larger roosts shared at least one element. Their sheer volume imposed severe damage on the trees that supported them, sometimes making the timber valueless. Walter Rader, who grew up on a farm in Monroe County, Indiana, in the 1860s, recalled hearing the nightly crash of breaking limbs from a pigeon roost in a nearby maple grove.33
In one early Tennessee roost, where the “screaming noise” of the birds could be heard for six miles, they “settled on the high forest trees, which they cover in the same manner as bees in swarms cover a bush, being piled one on the other, from the lowest to topmost boughs, which so laden, are seen continually bending and falling with their crushing weight, and presenting a scene of confusion and destruction, too strange to describe, and too dangerous to be approached by either man or beast.” Yet another old account (1801) from the Black River of the Mississippi Territory tells how the weight of the pigeons caused the branches to hang “down like the inverted bush of a broom.” It describes how “a hickory tree, of more than a foot in diameter, was alighted on by so many of these birds, that its top was bent down to the ground, and its roots started a little on the opposite side, so as to raise a bank.”34
Festooned over everything, pigeon dung distinguished the roosts as much as the dead and deformed trees. From that same roost on the Black River mentioned above, the author estimated that the amount of excrement carpeting the forest floor would fill “not only hundreds, but thousands of wagon loads.” The chemicals released from this prodigious deposition of fecal matter eliminated the understory and killed the trees “as if they had been girdled.” And the pungent aroma wafted for a mile, permeating the atmosphere with the scents reminiscent of a poultry farm.35
Western Kentucky hosted two major roosts of between four thousand and five thousand acres, plus several smaller ones. In the 1920s people could still provide firsthand information on the roosts back when they had been occupied by teeming pigeons. These elders coul
d place the roosts with great exactitude: “a large piece of ground where a country store now stands called Longview,” “around what is now the Jeff Davis Monument,” and “on Bacon’s Farm, one and a half miles South East of Ole Montgomery now.” What struck them most about these former pigeon grounds was the fertility of the soil: “best land in Christian County” or “land is most productive … of any other land in Graves County.” Eighty-eight-year-old Jasper Sisk summarized the fate of the old woods where the birds wintered: “They would roost in one place until they broke all the limbs off of the trees, then they would move to Joining timber & treat it likewise, then fire would break out in the old Roost and Destroy the remainder of the timber. The land was then put into cultivation & considered the best farming land.”36
WELCOME TO PIGEON CITY: NESTING
Generalizing about passenger pigeon nestings is difficult because they utilized virtually the entire diversity of wooded landscapes within their extensive range. They nested in single pairs, in small groups, in medium groups, and in vast colonies containing a hundred million birds or more. Pigeon cities tended to be longer than they were wide, which would have added considerable distance to potential food supplies over that required by a more compact configuration. Based on the dimensions of forty-seven nestings, Schorger came up with an average size of ten miles long and three miles wide.37 The largest of all was the one that formed near Sparta, Wisconsin, in 1871. L-shaped, it spread across 850 square miles, although not every bit of that area contained nests. The 1878 Petoskey, Michigan, nesting encompassed over 200 square miles, and another in Huron County, Ontario, around 1870, was almost square at thirteen miles by eleven miles. And in 1823, a nesting of 180 square miles took place in upstate New York.