Every year, between 200 and 100,000 species go extinct, according to the World Wildlife Fund. And yet few of these species have made as big an impression as passenger pigeons, which at their peak numbered around five billion. This year marks the 100th anniversary of their extinction and we are asking, have we learned anything since then?
Descriptions of passenger pigeons from the 1800s depict a phenomenon that is difficult to comprehend in this day and age. Flocks as large as 300 miles long and 1 mile wide would take over the sky, engulfing light from the sun for days in a thundering storm of beating wings and dung like ‘melting flakes of snow,’ according to John James Audubon.
Scientist and environmentalist Aldo Leopold once described watching the birds, writing: "The pigeon was a biological storm. He was the lightning that played between two opposing potentials of intolerable intensity"
The strength of passenger pigeons was flying in these large packs, intimidating predators and making it hard for them to hunt. But when the technological revolution came about, their strength became their weakness. They became easy prey for hunters with rifles, who could just shoot into the air and be sure to make a hit. Nets, as noted by TreeHugger readers, had an even more devastating impact; birds flew right in.
As more and more hunters took advantage of this cheap flying protein, passenger pigeon populations plummeted. Hunters kept track of the populations by communicating by telegraph until the last wild pigeon was shot in 1902. Twelve years later, the last captive pigeon, Martha, died.
Though the end of the passenger pigeon, a force of nature, had a profound effect on people in North America, it did not change the impact humans had on animal extinctions. In fact, the greatest number of animal extinctions caused by humans was in the 1900s (though we’re only at the beginning of the 2000s, so we can check our progress in 50 years).
Still today we over-exploit animals to the point of near extinction. Three quarters of global fish populations are caught at faster rates than they can reproduce, according to the Save Our Seas Foundation. Populations of tuna, cod and halibut have declined by 90 percent. What’s more, habitats are getting destroyed, making it harder for fish who manage to escape fishing nets to breed.
We almost saw the end of the American bison and various species of whales in the last century. The World Watch Institute estimates that one in four mammal species are in decline.
The numbers are grim, and most of them are caused by human activity. Though there is greater awareness about this problem, governmental actions are too slow –or sometimes not strong enough to stop poaching.
Some scientists are hopeful that they will be able to bring extinct species back from the grave. They hope to use DNA from stuffed passenger pigeon displays and genetic engineering to slowly reintroduce the birds..
One group working on this project is the Long Now Foundation. "De-extinction is not a 'quick fix' science," their co-founder, Stewart Brand wrote on their website. "Passenger pigeons, for example, will initially be bred in captivity by zoos, then placed into netted woods, and then finally re-introduced to portions of their original habitat — America's eastern deciduous forest. Before that happens, the U.S. Fish and Wildlife Service and regulatory agencies in the relevant states will have to agree to welcome the resurgent birds."
But this poses a conundrum. In the last hundred years, ecosystems in North America have adapted to the loss of passenger pigeons. Predators that fed on passenger pigeons, like foxes, eagles and owls altered their diet. Trees that relied on pigeons to spread their seeds, like white oaks and beech trees, found other ways of reproducing.
It is hard to guess the impact passenger pigeons could have on the environment if they returned. Some have raised concerns that the return of the passenger pigeon will negatively affect mourning dove populations.
That people should feel responsible for driving the birds to extinction is understandable, but what role should they play in bringing it back?