One hundred years ago, on Sept. 1, 1914, the last known passenger pigeon died in the Cincinnati Zoo. “Martha” was reported to have been at least 17 years old. Rarely, if ever, have we known the precise moment an entire species became extinct.
No one knows how many passenger pigeons once existed, but ornithologists estimate the population peaked between 2 billion and 3 billion in the mid-1800s. At that time they were the most abundant bird in North America. The largest numbers could be found in an area bounded by New England, Wisconsin, Ohio and Pennsylvania.
Descriptions of the numbers of passenger pigeons from the 1800s are legendary. Alexander Wilson, father of American ornithology, wrote of, “... such prodigious numbers, as almost to surpass belief; and which has no parallel among any other feathered tribes on earth, with which naturalists are acquainted.”
In 1813, John James Audubon reported a flight of pigeons along the Ohio River that darkened the sun for three days. “The light of noon-day,” he wrote, “was obscured as by an eclipse.”
Passenger pigeons lived almost exclusively in the eastern deciduous forest where beechnuts, acorns, and chestnuts were their primary foods. During the summer they ate soft mast such as blueberries, mulberries, grapes, and cherries.
It’s difficult to imagine how such an abundant species could be driven to extinction in only 50 or 60 years.
Several factors led to the ultimate extinction of passenger pigeons. As the eastern deciduous forest fell to development and colonial expansion, unbroken forest habitat began to disappear.
Because passenger pigeons occurred in such huge flocks, they were easy to kill, primarily for human consumption. Fat squabs still in the nest were in high demand. Hunters used every conceivable method to kill them. Market hunters shot, clubbed, trapped, and netted them. They built fires to smoke out nesting birds. They baited birds by tying captives (stool pigeons) to perches.
Still, how could people have killed so many birds in such a short period of time? The cost of ammunition alone would have been prohibitive for market hunters to have been totally responsible.
To comprehend just 1 billion of anything, consider this. If you had a billion dollars and you spent $1,000 every day, it would take more than 2,739 years to spend it all. And of course, the passenger pigeons were breeding every year to replenish their incredible numbers.
Unfortunately, the pigeon’s own biology worked against them. They nested only once a year and laid only a single egg, so their reproductive rate was very slow. Furthermore, they were nomadic and nested and roosted in huge flocks that were easy for hunters to find.
And though it’s impossible to prove today, there may have been a social component to their breeding biology that required huge numbers of nesting birds for reproduction to succeed. When the population dropped below a certain critical level, the demise of passenger pigeons may have been inevitable.
Habitat destruction, slow reproduction rate, and social behavior that required massive numbers of breeding birds were likely the passenger pigeon’s three strikes.
Though the passenger pigeon’s extinction is relatively recent, I shutter to think how modern America might react today if they still lived. Roosting flocks and nesting colonies were so huge branches broke from trees under their weight, and pigeon dung covering the ground beneath the roosts could be measured in inches.
Today we complain of flocks of 1,000 geese, 10,000 crows or 50,000 starlings despoiling parks, ball fields, and neighborhoods. Imagine backyards home to part of a flock of 300,000 passenger pigeons. Some might demand their extinction.
We have learned many ecological and biological lessons from the passenger pigeon. Perhaps the most important is that no matter how abundant a species might be, with sufficient motivation and without regulations, humans can exterminate it. That’s why the love of nature and conservation is so important.
For a more complete picture of the life and death of a species, consult “A Feathered River Across the Sky: The Passenger Pigeon’s Flight to Extinction” by Joel Greenberg (2014, Bloomsbury).
Shalaway can be heard 8 to 10 a.m. Saturdays on 1370 WVLY-AM (Wheeling) or online at www.watchdognetwork.com. Visit Scott’s web site www.drshalaway.com or contact him directly at firstname.lastname@example.org or 2222 Fish Ridge Road, Cameron, WV 26033.