An important anniversary passed quietly by recently. It was 93 years ago this month that the last individual of what had been estimated to be the world’s most abundant bird died. On September 1st 1914 ‘Martha’, the last surviving Passenger Pigeon in existence, was found dead in her cage in the Cincinatti Zoo. The following essay is written in her memory:

In Memory of Martha: 1885 - 1914

How do you think you would react to witnessing one of the most numerically staggering of all birding spectacles: billions and billions of birds flying in flocks so large they literally darken the sky? With wonder, joy, or by raising a gun? Our recent ancestors were faced with that choice - and ultimately their answer to that question means that you and I and everyone else alive today will never again have the chance to find out. The spectacle in question involved a bird that we will never see again: Ectopistes migratorius, the Passenger Pigeon.

Once the most most numerous bird on the planet, it’s thought that as recently as just two hundred years ago billions of Passenger Pigeons lived and fed in the enormous forests that covered the eastern United States. A.W. Schorger, in his book “The Passenger Pigeon: Its Natural History and Extinction” (University of Oklahoma Press, 1973), estimated that when the first Europeans arrived on the American continent the population of Passenger Pigeons was between 3 and 5 billion individuals (a number which is apparently close to how many individual birds of all species there are in North America now). Not only was one in every four of all the birds in this New World a Passenger Pigeon, they travelled around in vast flocks that roosted together in winter, migrated together in spring, and nested together in summer. A flock on the move must have been one of the most awe-inspiring natural sights ever recorded.

One of the first settlers in Virginia wrote that,`There are wild pigeons in winter beyond number or imagination, myself have seen three or four hours together flocks in the air, so thick that even have they shadowed the sky from us.’ Similar breathless reports can be found from the Dutch on Manhattan Island in 1625, from Salem in Massachusetts in 1631, and the first explorers in Louisiana in 1698. America’s most renowned wildlife artist John James Audubon (the illegitimate son of a French sea captain and plantation owner and his French mistress Jeanne Rabin, incidentally, which just goes to show how far in life you can get with a little determination) wrote of riding the 55 miles from Henderson, Kentucky, to Louisville one day in autumn 1813 under a sky darkened from horizon to horizon by a cloud of Passenger Pigeons. A local resident of Wayne County, New York wrote in 1854 that, `There would be days and days when the air was alive with them, hardly a break occurring in the flocks for half a day at a time. Flocks stretched as far as a person could see, one tier above another.’ Other reports from the mid to late 1800s describe flocks a mile wide streaming overhead for four or five hours during their migration in the early spring from their wintering areas in the Gulf states, Tennessee, and Arkansas to their breeding areas in New England, New York, Ohio and the southern Great Lakes area.[Clive Ponting's 'A Green History of the World', Penguin Books, 1992, (p168-170).]

In 1866 - just 150 years ago - a huge flock passed into southern Ontario: it was a mile wide, 300 miles long, and took 14 hours to pass a single point.

By any definition Passenger Pigeons were super-abundant. Incredibly though the last known nesting Passenger Pigeons were reported in the Great Lakes region in the 1890s, just thirty years after that massive flock was seen in southern Canada. The last two reports of wild individuals concern birds shot at Babcock, Wisconsin in 1899, and shot by a fourteen year old boy called Press Clay Southworth on his parent’s farm in Pike County, Ohio on March 24, 1900 [Lew Moores, Cincinatti Enquirer, Friday, March 24, 2000]. The last Passenger Pigeon on earth died alone after a lifetime’s captivity at about 1:00 pm on the 1st of September 1914. When Martha, as she was known, was found lying on the bottom of her cage at the Cincinnati Zoo that afternoon the most populous bird species that us humans had ever interacted with was extinct…

How on earth could a species so incredibly numerous become extinct in such a short time? There are three depressingly familiar strands to the answer: habitat destruction, reckless over-hunting, and constant disturbance of nesting colonies.

When Europeans first arrived in what would become known as North America they not only discovered unimaginably huge flocks of Passenger Pigeons but a country covered in trees. It’s estimated that in 1630 (around the beginning of European settlement) there were less than one million people - mostly Native Americans - living on the continent and more than one billion acres of forest land. From the air the eastern half of the continent would have looked green from one end to the other. Passenger Pigeons depended entirely on these trees. Conditions on a land mass with a stable level of forest cover had perfectly suited the evolution of a migratory bird that fed in enormous flocks on acorns, chestnuts and beech nuts, birds that could roam over a half million square miles of woods where warm summers and abundant rainfall produced huge food surpluses. As the forests in one area masted the flocks would find them, arriving like a feathered hurricane, stripping the trees bare and roosting in such vast numbers - some roosts apparently covered an area five miles by twelve - that branches broke under the pigeons’ weight and whole trees were toppled. By the time they moved on they’d have left behind them a mountain of firewood and a pile of droppings several inches deep.

It’s hard to imagine now just how chaotic these roosts must have been - and perhaps counter-intuitive to think that such a process would be sustainable or balanced. However the birds were simply moving around an enormous environment they were perfectly adapted to. As one part of this vast forest was being snapped into twigs, another - further north, west, or east - was just budding. As the birds moved on the trees would metaphorically breathe a sigh of relief, stick their roots into the nitrogen-rich guano and start rebuilding, while their seeds were carried off to be dispersed across the continent in the bellies of billions of pigeons.

Passenger Pigeons not only roosted in huge flocks, but like the terrestrial equivalent of seabirds they also nested in them. Breeding colonies could cover 50 square miles and the largest nesting ever described covered most of the southern two-thirds of Wisconsin, with other nestings in adjacent Minnesota. As many as 500 birds might nest in a single tree, straddling a pile of loose twigs on which they laid a single egg. If the egg survived to hatching, the pigeons would typically feed the nestling on a rich ‘milk’ until it was just two weeks old at which point the adults would leave, abandoning the squabs to live on their fat for a few days until they learned to feed themselves. Young pigeons developed quickly and within a few weeks the huge nesting grounds would be deserted. What they left behind them may not have been pleasant or pretty to look at, but the birds might not use the same site for decades allowing the trees plenty of time to recover.

Living in colonies of that size may have been possible when one half of North America was effectively a continuous forest, but the European immigrants wanted land and the trees were to a large extent “in the way”. The settlers built towns, they cleared land to keep livestock and plant crops and by 1880, for example, about 80% of the original forest cover of New England had been cut down. Deforestation occurred from east to west following the pattern and spread of settlement, and by 1907 the total area of forest had declined from 423 million hectares (or about 46 percent of the total land area) to an estimated 307 million hectares (or 34 percent of the total land area) - and much of what remained was to be found in the still relatively less-developed north and far west, far from the Passenger Pigeons normal range.
[http://fia.fs.fed.us/library/briefings-summaries-overviews/docs/ForestFactsMetric.pdf] [http://www.sciencenetlinks.com/lessons.cfm?BenchmarkID=5&DocID=374]

Tree Cover in the Eastern US: Pre-settlement and Present Day.
Copyright http://earthobservatory.nasa.gov

The oaks and the beeches of the east that provided the birds with food, with roosting and nesting sites, had largely been levelled to provide timber for housing, furniture, fences and fuel or cleared for farmland as the human population swelled from just over 5 million people in 1800, to 23 million in 1850, and on to 76 million by 1900. What had once been a huge and robust eco-system that had functioned very well for all concerned, became ever more fragmented and disrupted as more and more people poured into the country from an already degraded and largely deforested western Europe, slicing the once unpartitioned forests into smaller and smaller packets.

For several hundred years the human impact on the Passenger Pigeon would have been minimal - largely because of the small numbers of people living in North America compared with the vast numbers of birds. Native Americans had been eating the adult pigeons and their fat, juicy squabs for many years, and the first Europeans soon found that obtaining dinner in the nesting season needed nothing more sophisticated than a long stick and a strong arm - and if waving a stick around was too much bother the truly lazy could simply walk into a colony and scoop up some of the squabs that had fallen or been knocked from their nests. A few men with poles were never going to make a dent on the numbers of Passenger Pigeons, but introduce many men, guns and lead pellets into the equation and the balance can soon shift. While living in vast flocks is a good survival strategy when your main enemies are a few arboreal carnivores or aerial raptors - statistically your chance of ending up as a Peregrine’s dinner when you’re one individual in a flock of a billion is, to say the least, fairly low - it’s not as good when you’re being preyed on by hunters with firearms specifically looking for easy and plentiful targets.

At the same time as the human population was expanding rapidly technology was (literally) booming too, and a new generation of Americans began to turn their newly-acquired guns on the largest flocks of birds ever seen on the planet. From the early nineteenth century the historic literature suddenly fills with stories of men bringing down thirty or forty birds with a single shot, of an Ohio man blindly firing his 12-gauge pistol into a night-time roost and killing 18 pigeons, of hunting parties surrounding woodlands and killing every single Passenger Pigeon within them. Audubon wrote that, “The pigeons were picked up and piled in heaps, until each [hunter] had as many as he could possibly dispose of, when the hogs were let loose to feed on the remainder”, and described an encounter between a migrating flock and the local residents thus: “The pigeons passed in undiminished number, and continued to do so for three days in succession. The people were all in arms. The banks of the Ohio were crowded with men and boys, incessantly shooting at the pilgrims, which flew lower as they passed over the river. Multitudes were thus destroyed. For a week or more, the population fed on no flesh other that of pigeons, and talked of nothing but pigeons.”

The arrival of migrant pigeons was greeted everywhere by an orgy of killing. Local newspapers kept their readers informed of where the birds were, and every report seems to echo with the sound of shotguns: “…the woods and fields in this section are literally swarming with Pigeons. Our sportsmen are having a fine time shooting them,” is sadly typical. Just a few short years after their immense numbers had caused wonder and poets and writers had struggled to describe their feelings on seeing the flocks pass overhead, Passenger Pigeons touched the public soul so deeply that they were used in their hundreds of thousands as live targets in shooting galleries.

The next nail in the Passenger Pigeon’s coffin began to be driven home when subsistence hunting turned into ‘market hunting’ and a trade in pigeons developed. As villages developed into towns and towns into cities the demand for food grew too, and as our recent ancestors became more and more delerious about the seemingly limitless natural riches of “the bounteous land” the slaughter began in earnest. Not content with the numbers they could kill by shooting alone, market hunters devised a wide variety of techniques for slaughtering the adult birds and collecting their offspring. These magnificent, fast-flying birds were netted, baited with alcohol-soaked grain which made them drunk and easy to catch, and suffocated by fires of grass or sulfur that were lit below their nests. Trees were hacked down or set on fire to make the squabs jump from the nests. In an especially barbaric act live captive pigeons had their eyelids sewn shut and were set up as decoys on small perches called stools to attract flocks (one possible origin of the term ’stool pigeon’ for a person used as a decoy to entice criminals into a trap).

Suffering from habitat clearance and endless disturbance, the fate of the Passenger Pigeon was sealed with the onset of large-scale commercial hunting in the second half of the nineteenth century. As many as a thousand well-organised professionals supplied the developing cities on the east coast with what was considered no more than a cheap source of meat. The hunters, using scouts and the newly-installed telegraph system to find out where the pigeons were, followed roosting or nesting birds from site to site, destroying whole colonies. As the communication and transport infrastructure on the continent developed, the killing became more efficient and cost-effective.

New railroads, equipped with ‘freezer cars’, pushed out from the east towards the Great Lakes and Mid-west, enabling the hunters to get deeper and deeper into the interior and providing a way to transport absolutely staggering numbers of dead birds. By 1855 300,000 Passenger Pigeons a year were being sent to New York alone, in barrels stuffed with 5-600 birds each. The State of Michigan was both the Passenger Pigeon’s last stronghold and the markets’ main supplier. On just one day in July 1860 235,200 birds were transported out of the city of Grand Rapids. During 1874 Michigan’s Oceana County sent over 1,000,000 birds to the markets in the east and two years later was sending 400,000 a week at the height of the season. In 1869, Van Buren County, also in Michigan, sent a staggering 7,500,000 birds to the east. About three million birds were reportedly shipped by a single hunter in 1878. Even in 1880, when numbers had already been severely reduced, 527,000 birds were shipped east.

Amazingly just nine years later, in 1889, Michigan declared that the species was extinct in the State…and in 1897, in what would have been a laughable gesture if it weren’t so poignant, a bill was introduced in the Michigan legislature asking for a ten-year closed season on Passenger Pigeons.

It’s hard to imagine now that the potential repercussions of slaughter on this scale weren’t more widely recognised, but in the middle of the nineteenth century conservation practice was virtually non-existent and lawmakers simply saw no need to protect such an abundant species. A committee of the Ohio Legislature in 1857 was fairly typical when it stated bluntly that, Passenger Pigeons, “the most abundant and the most beautiful of American game birds,” needed no protection. When laws to protect the pigeons were enacted they were widely ignored. In 1886 an editor’s note in the New York-based magazine ‘Forest and Stream’ said: “When the birds appear all the male inhabitants of the neighborhood leave their customary occupations as farmers, bark-peelers, oil-scouts, wildcatters, and tavern loafers, and join in the work of capturing and marketing the game. The Pennsylvania law very plainly forbids the destruction of the pigeons on their nesting grounds, but no one pays any attention to the law, and the nesting birds have been killed by thousands and tens of thousands.”

Harassed at every stage of their lives the most numerous bird on the planet was pushed faster and faster towards extinction. Disturbance of the breeding birds had been so severe that the abandonment of whole colonies had become common. It’s difficult now to appreciate exactly how traumatic the constant shouting of the hunters and the remorseless pounding of their guns must have been for the shell-shocked birds, but for nearly thirty years, well over twice the lifetime of the average bird, there were no successful mass nestings at all. Reproduction virtually halted and replacement of the ageing population by young birds was largely eliminated. For the first time in the species’ history adult birds hugely outnumbered juveniles and immatures.

No species can possibly survive such an imbalance between young and old (or to put it more crudely, between the fertile and the infertile), and by the end of the nineteenth century it became apparent that Passenger Pigeons were becoming remarkably few and far between. A group of just ten birds caused headline news in the early 1890s, and in 1892 a Major Bendire wrote that, “It looks now as if their total extermination might be accomplished within the present century. The only thing which retards their complete extinction is that it no longer pays to net these birds, they being too scarce for this now, at least in the more settled portions of the country.”

The Passenger Pigeon may have been standing on the very edge of extinction by the end of the nineteenth-century, but we weren’t quite done having fun with it yet. In 1896 what was apparently the last remaining colony settled down to nest when, in yet another shameful episode in this benighted bird’s history, ’sportsmen’ gathered to kill what had been advertised as ‘the last wild flock’. The carnage was appalling: 200,000 pigeons dead, 40,000 mutilated, thousands of chicks destroyed or left to predators. Less than 5,000 of the flock survived. Shortly after the start of the twentieth century there were no new sightings at all…

The last chance for the survival of this highly mobile, migratory species - a bird evolved to fly hundreds of miles a day - appears to have been based around a group of captive Passenger Pigeons kept locked-up in a shed in Chicago by a Dr. Charles Otis Whitman. Sadly though, Dr Whitman, a biological scientist who had bought the birds from a Wisconsin dealer in 1896 just as the last individuals were disappearing from the wild, had bought the pigeons as part of a general study and provided neither the right diet nor the necessary stimuli for them to breed. [http://216.239.59.10] The birds lingered on for some years but didn’t reproduce, and one by one they withered away…

The Cincinnati Zoo acquired the remaining birds in 1902, but what had been intended to be a breeding group of Passenger Pigeons had dwindled to three birds by 1909, two males and a female - Martha, named after the wife of George Washington. One of the males died in 1910, and the other - the last male Passenger Pigeon - died in 1912. The Cincinnati Zoo offered $1,000 (an enormous sum for a bird that had once been valued at 50cents a dozen) for a male that it hoped would mate with Martha, but the reward was never claimed. Even if it had been, without being a part of the noise and the movement of the enormous flocks, without the atmosphere and clamour of the colony, Martha and her mate would have sat and blankly stared at each other until the end of their days.

Is there any doubt that this would have been the outcome? There must have been a point towards the end of the nineteenth century when tens of thousands of Passenger Pigeons still flew across the US. Commercial hunting had ended when it had become no longer economically profitable, and large stretches of potentially suitable habitat remained (although many of the largest nut-producing trees that the pigeons depended on had been logged and ‘masting’ may not have occurred at all some years). But to breed successfully Passenger Pigeons needed to nest in vast colonies, not in the relative solitude of a few remnant groups. Perhaps, as has been suggested, colonial breeding enabled them to swamp predators with their enormous numbers (its believed that by 1892 the majority of birds were no longer breeding in colonies but in isolated pairs making them vulnerable to predation), but surely colonies this size moved way beyond ’swamping’ into providing the most accessible feast on the continent, ringing a dinner-bell for every predator within miles? On an individual level colonial living is advantageous (provided that you’re one of the individuals able to find nesting space and sufficient food to raise your young of course) as you’re less likely to be individually picked off when there are millions of others just like you within easy reach, but it seems just as likely that having evolved to live in crowds, to have been part of the most extraordinary mass movements of birds anywhere on the planet, they were also biologically hard-wired to function as part of a colony. Being ‘part of the throng’ suited them just as it suits many other species and they simply wouldn’t have bred in the hushed confines of a cage or an aviary (indeed the fate of the Passenger Pigeon illustrates a very important principle of conservation biology: it is not always necessary to kill the last pair of a species for it to be driven into extinction).

Has the Passenger Pigeon really disappeared? There were still sightings being claimed into the 1930s, but none were substantiated, and whilst there is always hope that a more solitary species might possibly be surviving somewhere in a remote forest (the Ivory-billed Woodpecker comes to mind) there is none at all that such a specialised, gregarious one will be. The occasional report is still made by hopeful observers but these are always of Mourning Doves, a smaller and very widespread dove that has adapted to living alongside man and has suffered far less as a result. No, if we want to see a Passenger Pigeon the only way is to go and look at one of the 1500 or so mounted specimens (what a dispassionate term ‘mounted specimen’ sounds set against such a sad story) held in museums and collections around the US.

The last wild Passenger Pigeon, shot by young Press Southworth, is on display at the Ohio Historical Society in Columbus: ask to see ‘Buttons’, the trivial name this historically supremely significant bird was given because the taxidermist used black shoe buttons for its eyes. If you’re in Washington DC you might even get permission to go and see Martha herself: after she died she was packed in a 300lb block of ice and sent to the Smithsonian Institute where her faded, fluid-preserved body sits on a branch to this day - alone in death as she was in life…

So the Passenger Pigeon is gone. We’ve had demonstrated how quickly and totally we impact on our environment, and surely the lessons of loss have been learned? Of course not. There are more species at risk of extinction now than at any other time in our history: and one particular species - one estimated to number around six billion now and thought likely to reach ten billion in another few decades - needs to realise right now that life is not as permanent and unchanging as it might like to believe…