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At least 500 species and
subspecies of plants and animals have gone extinct in North America
since the 1500s; among them, the great auk, the Labrador duck,
the heath hen, the Eskimo curlew, and the sea mink. Natural causes
appear to have claimed just one, a marine snail. We barely got
to know many of the others. These excerpts from the book written
by Douglas H. Chadwick and photographed by Joel
Sartore, depict a few survivors.
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Florida panther
This mangy Florida panther photographed itself by tripping an
infrared beam. When wildlife biologists saw the photograph they
were enthusiastic about how much better the panther looked since
theyd last seen it. Besides mange, Number 51
is believed to be suffering from ringworm as welldiseases
unknown in healthy populations of mountain lions elsewhere in
the U.S. (Regionally, Felis concolor coryi is called mountain
lion, cougar, puma, panther, painter, and just plain lion.)
More than a century of inbreeding has seriously depleted the panthers
gene pool, making them subject to disease, congenital defects,
reproductive failure, and other calamities. Healthy cougars from
west Texas have been introduced into the panthers south
Florida range with the hope that interbreeding the subspecies
will produce offspring with a healthier genetic mix. Ironically,
saving this subspecies may well require diluting its genetic distinctiveness.
Because an adult panther needs a lot of room to roam, the available
habitat in the Big Cypress Swamp and along the edges of the Everglades
may never support many more than the 30 to 50 panthers now prowling
south Floridas wildlands.
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California condor
Oblivious to the fundamental questions posed and the furor raised
by their tenuous existence, these hungry, captive-bred juvenile
condors eagerly feed on handouts from their human protectors in
the California Condor Recovery Team. Every three days, biologists
chain part of a stillborn calf carcass to this rock in Los Padres
National Foresteasy pickings free of the coyote poisons,
lead bullets and shotgun pellets, pesticides, and other carrion
contaminants that almost exterminated the condor.
The 1986 decision to capture all the remaining condors for a last-ditch
captive-breeding program raised troubling questions about the
role of natural extinction in evolution and wildlife conservationquestions
with which the wildlife community was ill prepared to wrestle.
Condors are now being returned to the wild and to a world in which
they were already declining before Europeans set foot on this
continent.
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Red wolf
The first endangered species for which a recovery plan was put
in place, and the first predatory mammal ever reintroduced to
the wild, the red wolf has rebounded from just 17 animals to approximately
300. From captive-breeding facilities red wolves have been released
on public wildlands in North Carolina and Tennessee, where they
are now breeding. If they stray too far, they are soft-trapped
and returned to their isolation from human neighborhoods.
Having survived hunting, trapping, poisoning, the destruction
or alteration of much of its original habitat, and the extinction
of two of its three subspecies, the red wolf faces new peril.
Recent DNA studies have failed to distinguish between red wolves
and wolf-coyote hydrids. More studies, and a scientific review
of endangered species management, are underway.
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Vernal pool tadpole shrimp
Evolution has adapted these living fossils to drought, flood,
heat, and cold, but vernal pool tadpole shrimp havent
been well prepared to cope with the ways of human beings. These
bottom-scuttling creatures live just long enough to hatch, grow,
mate, and lay eggsmaybe three months. Then the vernal
pools in which they live dry up, and the unhatched eggs must wait
several weeks, or even years, in the dried mud of their ephemeral
home pools.
A few eggs may be transplanted to other vernal pools on the legs
of wading birds or in the mud-matted hair of mammals, which is
why saving individual pools may not be enough, and why preservation
of the pool complexes that define a population is so important
to the species survival. Other eggs succumb to water projects,
urban sprawl, agriculture, roads, off-road vehiclesthe
forces that have destroyed some 90 percent of all the vernal pools
in Californias Central Valley, formerly prime habitat
for the tadpole shrimp.
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©1996 National Geographic Society.
All rights reserved.
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