On Sept. 1, 1914, the last known passenger pigeon died in the Cincinnati Zoo. Rarely, if ever, have we known the precise moment an entire species became extinct.
Ornithologists estimate the pigeon population peaked at 2 billion to 3 billion individuals in the mid 1800s, making it 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. In 1813 John James Audubon once 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 forests where beechnuts, acorns and chestnuts were their primary foods. During the summer they ate soft mast such as blueberries, mulberries, grapes and cherries.
Several factors led to the ultimate extinction of passenger pigeons. As the forests they inhabited fell to development, unbroken forest habitat began to disappear.
Because passenger pigeons occurred in huge flocks, they were easy to kill, primarily for human consumption. Fat squabs still in the nest were in high demand. 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.
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 is impossible to prove today, there may have been a social component to their breeding biology that required huge numbers of nesting pigeons for reproduction to succeed. When the population dropped below a certain critical level, the demise of passenger pigeons may have been inevitable.
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 (Bloomsbury, 2014).
Biologist, author and broadcaster Scott Shalaway can be heard 8-10 a.m. Saturdays on 1370 WVLY-AM (Wheeling) and online at www.wvly.net. He can be reached at www.drshalaway.com, firstname.lastname@example.org and 2222 Fish Ridge Road, Cameron, W.Va., 26033.