By SARA ARTHURS
Once the passenger pigeon was so numerous that, when a flock passed overhead, the sky would darken for hours. By 1914 the bird was extinct.
A century later, wildlife conservationists strive to raise awareness of its life and what its extinction might mean for other species.
The passenger pigeon was related to the mourning dove and the rock dove, which is what is commonly referred to as “pigeon” today. It lived throughout the eastern United States and Canada.
Researcher Joel Greenberg, of Westmont, Illinois, said the bird’s extinction has ramifications even today.
In a phone interview held the same day Toledo lifted a ban on drinking water after toxins got into the city’s supply, Greenberg said much can be learned from the passenger pigeon.
“There is no better cautionary tale (than the passenger pigeon) to the proposition that no matter how common something is — and it could be water, it could be fuel, it could be something alive — if we’re not good stewards we could lose it,” Greenberg said.
Greenberg is author of the book “A Feathered River Across the Sky: The Passenger Pigeon’s Flight to Extinction” and co-producer of a PBS documentary on the passenger pigeon, “From Billions to None.” He is a leader on Project Passenger Pigeon, an effort to educate people about the bird.
Project Passenger Pigeon has sought out involvement from universities, museums, parks and zoos around the country, with more than 190 institutions participating.
“Our goal was to tell people the story about the bird. … It’s a powerful story,” Greenberg said.
In Ohio, passenger pigeons nested in large numbers in the 1860s but that began to diminish by about 1870, Greenberg said.
He encountered stories of passenger pigeons flying over Columbus and when they darkened the sky, people thought that the world was ending and “the end times were arriving. … The downdraft from the beating of hundreds of millions of wings made people cold.”
Ohio was “right in the center of its range,” said Bill Thompson III, president of the Ohio Ornithological Society and editor of Bird Watchers Digest, which is published in Marietta.
The last passenger pigeon, “Martha,” died in captivity Sept. 1, 1914, at the Cincinnati Zoo. The last wild bird was seen in 1902.
No one knows exactly how many passenger pigeons there were but “there were estimates of billions,” said John Windau, wildlife communications specialist with the Ohio Department of Natural Resources’ Division of Wildlife District 2 office in Findlay.
They mostly nested in large forested areas of oaks and beechnuts. They nested once a year, laying one egg. An article in “Ohio Conservation Bulletin” from May 1965 reported that as many as 100 nests might be found in a tree. The article reports that tree limbs, and even whole trees, would crack under the weight of birds and nests.
One factor contributing to the extinction is that the birds were “very social, gregarious nesters” in large flocks and colonies, Windau said. Once the population started to decline, it was harder for the birds to breed because there were fewer of them and they had less social interaction.
Greenberg said passenger pigeons were known to eat plants and insects but preferred acorns and beechnuts, especially during nesting season.
There were several factors leading to the bird’s extinction but human activities played a major role, Windau said.
The birds were widely hunted, sometimes for sport, but mostly as a source of meat.
“At that time hunting was not regulated,” Windau said, so, people could kill as many birds as they wanted with any means they wanted.
In the 19th century, new technology allowed hunters to monitor the birds’ presence by telegraph and to quickly get the meat to urban markets by railroad, Greenberg said.
“The burgeoning urban centers of the Midwest and East could now get vast supplies,” Greenberg said.
So instead of a hunter shooting just a few pigeons to eat with family, professional hunters would shoot them in large numbers.
At the same time, humans were expanding into areas where the birds lived, cutting down trees that were their nesting sites and food sources in order to make room for farming. Since the pigeons only laid one egg a year, the potential for reproduction was limited, Greenberg said.
“The hard lesson of the passenger pigeon is that it was once so numerous,” Thompson said. “I mean, billions of birds.”
Thompson said there is “nothing wrong with hunting” and noted that, in Ohio, hunting season controls the deer population. The unregulated nature of hunting of the passenger pigeon’s day, though, still goes on in some other countries, he said.
It wasn’t until decades after the passenger pigeon’s extinction that humans “realized, wow, we completely did that ourselves,” Thompson said.
Windau said the extinction of the passenger pigeon has affected the way scientists look at wildlife conservation today.
The fact that there was a population of billions “and within two decades it was gone” made people wake up to the realization that it could happen. Windau said in the 1850s there was some discussion of legislation to protect the passenger pigeon but it wasn’t seen as necessary.
After the passenger pigeon’s extinction, scientists looked at the birds’ ecological impacts. Greenberg said there is a theory that, had the passenger pigeon survived, Lyme disease would be less prevalent today. This is because the mice that harbor Lyme disease are more numerous when acorns are plentiful, and passenger pigeons would have competed with them for that food, reducing the mice population.
Thompson said today there is more study on why a species’ population might be shrinking.
“There are a lot of success stories,” Thompson said.
He cited the California condor, once on the verge of extinction. Scientists learned that condors were particularly susceptible to several hazards: eating poisoned animals that had been put out to kill coyotes; lead poisoning from lead ammunition; and drinking antifreeze. When human habits changed, such as banning lead ammunition, their numbers went up, Thompson said.
He thinks the public reacts to such opportunities to help save a species.
“People get behind it,” he said. “Everyone likes to hear a success story.”
Windau said the bald eagle is “a perfect example” of another success story. At one time, the bald eagle was federally endangered, but with changes in pesticide use and efforts to protect wetlands their numbers have increased. In the lower 48 states, according to a recent Reuters article, nesting pairs rose from 400 in 1963 to 10,000 by 2007, when the United States removed the bald eagle from its endangered species list.
In Ohio there are a number of species that are endangered or threatened. Windau said bats are particularly at risk because of a fungus that is decimating bat populations.
The Ohio Ornithological Society and the Cincinnati Zoo and Botanical Garden will co-host a symposium on the passenger pigeon this weekend. Thompson said it’s in a sense a memorial weekend for the passenger pigeon.
Greenberg will speak, along with experts on extinction and on Ohio birds and wildlife. The zoo will also host a Twitter chat Wednesday.
On Monday, the zoo’s newly renovated memorial to Martha will be unveiled. Tiffany Barnes, public relations manager for the zoo, said the zoo is asking visitors to ask themselves what they’re doing now to ensure that today’s wildlife will be around 100 years from now.
“I think that is kind of the lesson that Martha can teach us all,” Barnes said.
The loss of the passenger pigeon is a reminder that the world is a fragile place “and we need to do what we can to be good stewards so there’s not a cardinal memorial symposium or a bald eagle memorial symposium,” Thompson said.
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