By
Bob Norberg, The Press Democrat, 1/15/13
It
seemed like an odd idea at the time, building tunnels under a busy road to help
California tiger salamanders travel safely from their hillside homes to a
nearby pond where the endangered species can breed.
The
plan, however, appears to have worked, according to biologists who are studying
the tunnels, built two years ago under Stony Point Road near Cotati.
"I
haven't analyzed all the data. Everything is preliminary, but just a broad
general conclusion is these crossing tunnels are working. They are functional,
and salamanders are using them," said Tracy Bain, a graduate student at Sonoma State University.
The
San Francisco resident is writing her thesis on the effectiveness of the
tunnels for a masters degree in conservation biology.
"There
are lots of things that fragment habitat of migrating animals," Bain said.
"For these salamanders, who go from their upland habitat, where they are
year-around, to the pond, the road is the problem."
The
tunnels were constructed two years ago by Sonoma County, using a $150,000 grant
from a Caltrans fund to offset environmental effects of roadwork.
It
was an idea proposed four years ago by David Cook, a senior environmental
specialist for the Sonoma County Water Agency who studies amphibians, such as
frogs and salamanders.
California
tiger salamanders are 8-inch amphibians with bright spots that live in gopher
holes but come out during the first evening rains of winter, migrating as far
as a half-mile to breed in ponds.
One
such breeding area is near Cotati, where the tiger salamanders live in the
uphill grasslands on one side of Stony Point Road. The breeding ponds, where
they lay their eggs, is on the other side of the road.
"I
was doing wildlife studies for a Water Agency proposed pipeline in the area and
I found this major migration route that crosses Stony Point and a frequent
mortality," Cook said.
The
salamanders were listed as an endangered species in Sonoma County in 2003 by
the U.S. Fish and Wildlife Service, becoming a lightning rod for criticism by
developers and growth advocates, who complain the amphibians' protected status
holds up projects.
Cook
said, however, it is no different than protecting salmon, also on the
endangered species list, and tunnels are no different than fish ladders.
Before
the tunnels were built, the half-mile stretch of Stony Point Road was a
"blood bath" as the salamanders were crushed by cars as they tried to
cross the road, Cook said.
He
said there could be several hundred salamanders that live in the area, although
the number is difficult to estimate because they live underground.
"It
is the only known breeding pond in the area. Salamanders living on the other side
of the road have to cross to reproduce, and if they don't, the population will
start to decline," Cook said.
The
10-inch steel pipes are about 35 feet long, with foot-high plastic fencing that acts as funnels to guide the
salamanders in.
On
recent rainy nights, Bain and some helpers have gathered at the road, picking
up salamanders and putting them near the entrances of the pipes.
Sometimes
it takes more than one attempt, but many of the 100 salamanders they found did
make their way through the tunnels and back.
Even
after they left, infrared cameras recorded salamanders using the
tunnels without any help from the researchers.
"It
doesn't mean the tunnels will save the species from extinction statewide, but
in this area, it turned out to be a good idea," Cook said.
(You
can reach Staff Writer Bob Norberg at 521-5206 or bob.norberg@pressdemocrat.com.)
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