It was the moment that humanity learned we had the awesome power to
erase an entire species off the face of the Earth in the scientific
equivalent of a blink of an eye: The passenger pigeon went from billions
of birds to extinct before our very eyes.
It was one bird's death after many. But a century ago,
Martha, a red-eyed, grey and brown bird famous as the last surviving
passenger pigeon, keeled over, marking an extinction that shook science
and the public.
Now, a century later, Martha's back, in a way. She is
being taken out of the file cabinets of history in a new Smithsonian
Institution exhibit this month, reminding the public of her death, and
of other species that have gone extinct because of man. A new
scientific study this week shows how pigeon populations fluctuated
wildly, but how people ultimately killed off the species.
And some geneticists are even working on the longshot hope of reviving the passenger pigeon from leftover DNA in stuffed birds.
"Here was a bird like the robin that everybody knew and
within a generation or two it was gone — and we were its cause, " Duke
University ecologist Stuart Pimm said.
In the 18th and 19th centuries the passenger pigeon was
the most abundant bird species on Earth. In 1866 in Ontario, just one
flock of billions of birds, 300 miles long and one mile wide, darkened
the skies for 14 hours as they flew by overhead. Unlike the domesticated
carrier pigeon used for messages, these were wild birds.
They were easy to catch because they stayed together.
They were considered a poor man's food; domestic workers complained
about eating too much passenger pigeon.
"Nobody ever dreamed that a bird that common could be
brought into extinction that quickly," said University of Minnesota
evolutionary biologist Bob Zink.
Examination of the passenger pigeon's genetic code
shows that their population ping-ponged regularly from as much as 5
billion to as few as tens of millions, said a study co-authored by Zink
in the journal Proceedings of the National Academy of Sciences released
Monday. Still, the chief causes of the extinction — cutting down Eastern
U.S. forests and hunting — were man-made, Zink said.
"Passenger pigeons always reached lows like this, it's just this time their luck ran out because we were around," Zink said.
By 1900, there we no passenger pigeons left in the
wild. By 1914, there was just 29-year-old Martha at the Cincinnati Zoo.
People lined up to see her. She was a star.
Then on Sept. 1, 1914, Martha was found lying on the
bottom of her cage. The passenger pigeon was now extinct. It had gone
from billions of birds to zero in about one century, probably less.
It was the first public extinction, something people
used to think happened only to relics of the past like dinosaurs, or
critters stuck on islands like dodos, Pimm and other scientists said.
"This was a real wake-up call for the public and
frankly for scientists too," said Helen James, curator of birds at the
Smithsonian Natural History Museum. "Ornithologists studied birds and
they didn't really think of species becoming extinct."
But they did. And Martha, the last of her kind, was put
in a 300-pound block of ice and shipped to Washington D.C. and the
Smithsonian. She was stuffed and mounted, continuing as a star. When she
traveled back to Cincinnati or to San Diego for a big conservation
conference, she flew in a first class seat.
But her star faded. For the last 15 years, she has been
in a drab metal filing cabinet in the bowels of the Smithsonian, stuck
on the same stick with an older stuffed unrelated pigeon named George.
On Monday, they were separated, George was put back in storage and a
prettied up Martha was ready for a comeback. An exhibit on her
extinction and the 100th anniversary starts June 24 at the Smithsonian.
And if scientists can figure it out, there may be a
bigger comeback in the offing. The passenger pigeon is the prime
candidate for something new: de-extinction.
Some top geneticists in a non-profit are looking to see
if they can create new living versions of the passenger pigeon, by
editing the DNA of the closely related band-tailed pigeons, growing
those birds from embryo and breeding them. It would cost millions and
take at least a decade, said Ben Novak, lead researcher of the group,
Revive & Restore of San Francisco.
Pimm and Zink don't like the idea ethically or practically.
Novak sees a world on the verge of a mass extinction of
many species and feels something has to be done about it. Reviving some
long-lost species may offer "a type of justice for what we're doing
now" and also teach people "it's so much easier to keep something alive
than to bring it back to life."
Story Source:
http://www.newsdaily.com
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