The Sixth Extinction: An Unnatural History

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Cohn-Haft identified as a yellow-tufted woodpecker, a black-tailed tityra,
and a golden-winged parakeet. He trained the scope on a speck of blue
that turned out to be the most beautiful bird I have ever seen: a red-
legged honeycreeper, with a sapphire breast, scarlet legs, and a cap of
brilliant aquamarine.
As the sun rose higher and the calls grew less frequent, we set out
again. By the time the day had turned furnace-like and we were both
dripping with sweat, we got to the chained gate that marks the entrance
to Reserve 1202. Cohn-Haft chose one of the paths that have been cut into
the reserve for access, and we tromped to what he thought was roughly
the square’s center. He stopped to listen. There wasn’t much to hear.
“Right now I’m hearing only two bird species,” he told me. “One of
them sounds like it’s saying, ‘Whoops, looks like rain,’ and that’s a
plumbeous pigeon. It’s a classic primary forest species. The other is doing
this ‘choodle, choodle, peep’ kind of thing.” He made a sound like a flutist
doing warm-up exercises. “And that’s a rufous-browed peppershrike. And
that’s a typical second-growth or edge-of-pasture species that we
wouldn’t hear in primary forest.”
Cohn-Haft explained that when he had first worked at Reserve 1202 his
job was to catch and band birds and then release them, a process known
by the shorthand “ring and fling.” The birds were caught in nets strung
across the forest from the ground to a height of six feet. Bird censuses
were conducted before the forest fragments were isolated and then
afterward, so that the numbers could be compared. Across the reserves—
there are eleven in total—Cohn-Haft and his colleagues banded nearly
twenty-five thousand birds.
“The first result that kind of surprised everyone, although it’s sort of
trivial in the grand scheme of things, was kind of a refugee effect,” he said,
as we stood in the shadows. “What happened when you cut down the
surrounding forest is that the capture rate—just the number of birds you
captured and the number of species sometimes, too—went up for about
the first year.” Apparently, birds from the deforested areas were seeking

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