California’s only native turtle species released in East County
Reptile specialists with the San Diego Zoo, along with
state and federal scientists, released five juvenile members of California's
only native turtle species at the Sycuan Peak Ecological Reserve in the East
County on Wednesday, the zoo reported.
The western pond turtles are part of a “headstarting” program in which
the turtles are raised in captivity until they are large enough to defend
themselves from predators.
The western pond turtles used to be widespread along the Pacific Coast
states, but their numbers have shrunk in Southern California due to habitat
loss and non-native predators like bullfrogs and largemouth bass, which eat up
hatchling turtles that measure no larger than a quarter.
“Three years ago, we collected (pregnant) female pond turtles from the
Sweetwater River at the Sycuan Peak Ecological Reserve and brought them to the
San Diego Zoo to lay their eggs,” said Chris Brown, a reptile ecologist with
the U.S. Geological Survey's Western Ecological Research Center.
“We wanted to raise their offspring in captivity until they were large
enough to avoid being eaten by predators,” Brown said. “In the meantime, we
removed non-native predators from the river within the Ecological Reserve so we
could introduce these baby turtles back into a safer, more natural habitat.”
According to the zoo, ecologists went 10 years without finding the
species of turtle in the Sweetwater River. However, some juveniles have been
found there in the past three years, since habitat restoration efforts and the
removal of invasive predators started.
“We have been studying western pond turtles in Southern California for
many years and know that they are struggling, particularly in San Diego
County,” said Thomas Owens, senior keeper with the San Diego Zoo's Department
The five turtles released in the reserve are about the size of an
iPhone, big enough to wear miniature radio transmitters. Researchers attached
tiny antennae to the baby turtle's shells so they can regularly check on the
reptiles' growth, physical health and behavior.
The mothers were previously returned to the area. More young turtles are
being reared by the San Diego Zoo, and they will be released into the wild
once they reach sufficient size, zoo officials said.