Last Stand for U.S. Ocelots?
After decades of habitat loss and vehicular deaths, only 50 of the cats are left in a corner of Texas.
Photograph by Joel Sartore, National Geographic Creative
National Geographic
Published June 3, 2014
Last November in Texas, a feline twice the size of a house cat was struck dead on State Highway 100, just south of Laguna Atascosa National Wildlife Refuge in the Rio Grande Valley.
Mountain lions (another name
for the panther) imported from Texas helped the Florida panther recover
by introducing genetic variability. So it's only fitting that Texas
ocelots may soon receive their own new pair of genes.
Leo
Gustafson, the refuge's assistant manager, went out to inspect the
corpse. He soon found himself gazing at the cat's beautiful tawny coat,
covered with spots, bars, and splotches—the perfect camouflage for a
thorn-scrub habitat of sun and shade. But the pattern had proved useless
as the ocelot tried to cross the four-lane divided highway.
Gustafson
noted the thick radio collar around the cat's neck and recognized the
individual as the four-and-a-half-year-old male that refuge staff had
been tracking. Over the past few months, they had watched with
trepidation as he crisscrossed a patchwork of cotton fields and
convenience stores, culverts and roadways, seeking to establish a
territory and find a mate.
"It's tragic, really," said refuge manager Boyd Blihovde. "Ocelots are so beautiful and so rare, and to lose so many of these animals to vehicular collision just seems senseless."
The
death of the cat wildlife biologists knew as OM276 (OM stands for
"ocelot male") also brought the species one step closer to extinction in
the United States.
Ocelots still inhabit Mexico and
every country south of it except Chile. But the last ones left in the
United States—an estimated 50 individuals, down from about a hundred a
decade ago—live in two separate populations in and around Laguna
Atascosa and on private land in neighboring Willacy County.
This
is the species' last foothold in a territory that once included Texas,
Louisiana, Arkansas, and Arizona. (Five ocelots have been sighted in
Arizona in the past five years, but researchers say the possibility of a
breeding population there is highly unlikely.)
An Unfriendly Environment
The
number one cause of ocelot deaths in the U.S. today is vehicular. Six
of the 14 cats tracked with radio telemetry by the U.S. Fish and
Wildlife Service and Laguna Atascosa biologists have been killed by
vehicles. As Blihovde puts it, "Wildcats and highways don't mix."
Yet cars and trucks aren't an ocelot's biggest foe. Habitat loss and fragmentation are.
Some
95 percent of the cats' native habitat in the U.S. has been converted
to agriculture or become urban sprawl. In the Rio Grande Valley—a border
area that's one of the nation's fastest growing regions—young males
like OM276 that venture outside the refuge must navigate a dangerous
man-made landscape.
Cause for Hope?
Now, after decades of inaction, some recovery measures are finally under way.
This year the Texas Department of Transportation plans to install the state's first highway wildlife crossings for ocelots. Eight underpasses, at a cost of $1.4 million, will be incorporated into the expansion of Highway 106.
Such
crossings, accompanied by highway fencing, have proved successful
elsewhere in the U.S. In the 1980s, for instance, when Interstate 75
(aka Alligator Alley) was widened though the Everglades, Florida
invested $20 million to build 23 crossings. Today the state's endangered
panther population, which numbered no more than 50 in the mid-1990s,
has bounced back to an estimated 160.
Researchers from the ocelot "translocation" team—which includes the U.S. Fish and Wildlife Service
and various universities and institutions in the United States and
Mexico—plan to appeal to the Mexican government for permission to import
breeding-age females from Tamaulipas, Mexico, where an estimated
thousand ocelots live.
Ocelots Need Room to Roam
Ultimately, the ocelot's recovery depends on finding enough room for the population to expand.
The
Fish and Wildlife Service says it wants to buy land or secure easements
to create habitat corridors. But to date the agency has purchased only
about 100,000 of the estimated one million acres (405,000 hectares) of
habitat the cats need to recover. In Texas, which is 95 percent
privately owned, landowner incentives to restore ocelot habitat may
offer the best hope to conserve the species.
In the face
of such grim realities, each new ocelot birth is significant. So on
February 14, when a juvenile never seen before took a selfie with one of the refuge's wildlife trip cameras, Laguna Atascosa staff felt like they'd received a valentine.
When wildlife biologist Hilary Swarts
tracked and radio-collared the animal a few weeks later, she confirmed
that it was a 10- to 12-month-old juvenile female. Then in late April,
another new juvenile, a 12- to 14-month-old male, was discovered on the
refuge.
Two new kids on the block are hardly enough to
pull the species back from the brink. But for an imperiled species like
the ocelot, every kitten is a sign of hope—and a step in the right
direction.
No comments:
Post a Comment