Call it a Head Start program for western pond turtles, a species that certainly needs a helping hand. Bullfrogs, disease and habitat loss drove the state’s population down to about 150 in three isolated areas in 1990.
Extinction in this state was just around the pond.
“It was the impetus to go into action and learn the best way to start producing eggs or lose the population in Washington,” said state Department of Fish and Wildlife biologist Michelle Tirhi, who manages one of the recovery areas.
In 1991 the department and the Woodland Park Zoo teamed up in the Western Pond Turtle Recovery Program.
Science, patience and nature combined to raise hopes for a self-sustaining population.
Ninety more turtles were released in Western Washington earlier this month, helping to bring the population to about 1,500.
Boosting the population includes trapping turtles in the spring and outfitting older females with transmitters. Females don’t breed until they are 10- to 12 years old, and even then, only about 15 percent of hatchlings survive in the wild.
The nesting period for western pond turtles is from May to mid-July, when the females emerge from the water seeking suitable nesting sites. Thanks to the transmitters, the females are tracked about 12 hours each day, Tirhi said.
“We track only the females because we’re interested in increasing the population, and that means protecting females’ nests and eggs, taking eggs to the zoo, hatching and rearing until they’re released,” she said.
To find the nests, watchers use spotting scopes to track female turtles and keep their distance.
“Turtles are slow, and they tend to meander slowly. They stop for a long time. When you see one start to dig you have to keep eyes on her. You wait until she’s done laying eggs and backfills the hole,” Tirhi said.
“The minute we see her go back to the pond as fast as she can, we put a wire cage over that nest and nail it down so predators can’t dig it up. We uncover the nest and put in temperature and moisture probes to see which (statistics) provide a more successful guide to a successful nest.”
In the south Puget Sound area, females lay an average of seven eggs. For the past several years, eggs have been left in the ground to incubate, but the hatching rate in Tirhi’s area started to decline.
Last year only 40 percent of the eggs hatched. Predators run the gamut of species: the invasive bullfrog, the biggest threat to baby turtles; and ospreys, eagles, foxes, raccoons, coyotes, otters, mink and beavers.
“This year, we immediately collected half of the eggs, took them to the zoo, and put them in an incubator. The other half was left to see which would be more successful.”
Little turtles are released back to the wild when they are 10 months old. At that point, they are about the size of a 3-year-old turtle in the wild, thanks to being fed all winter rather than hibernating.
Native western pond turtles are found on the west side of the Cascades; the native painted turtle on the east side. They are both threatened by a nonnative turtle, the red-eared slider, introduced through the pet trade.
“People get sick of them and let them go in local ponds. They’re very prolific, very opportunistic and very aggressive … and they’re all over the state,” Tirhi said.
Her alternative to turtle abandonment: “Call a local pet store and say, ‘I’ve been advised by the state that this is a pest and that it should go back to the pet store trade.’ They usually take it.”
Tirhi is a fan of the western pond turtles.
“These turtles are really incredible in the sense of their simplicity. They’re just a very gentle species to work with, the type of species that you fall in love with and want to try to protect.”
Columnist Sharon Wootton can be reached at 360-468-3964 or www.songandword.com.
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