Woodland Park Zoo Provides a Head-Start to Endangered Turtles

Posted By : The Animal Facts Editorial Team

Date: August 22, 2020 11:30 pm

A western pond turtle prior to its release

Photo Credit: Jeremy Dwyer-Lindgren/Woodland Park Zoo

Woodland Park Zoo in the United States and the Washington Department of Fish and Wildlife (WDFW) have celebrated the release of 24 Western pond turtles.

The 24 turtles are part of the head-start program which aims to give these endangered turtles a fighting chance at life. Hatchling turtles are collected after they hatch and raised at Woodland Park and Oregon Zoo’s until they reach a size where they are less vulnerable to predation.

This program began in 1991 and is the longest running wildlife release program in Washington State.

A western pond turtle prior to its release

Photo Credit: Jeremy Dwyer-Lindgren/Woodland Park Zoo

Each spring biologists with the WDFW travel in the field and tag adult turtles with a transmitter which allows them to find the nesting sites of the turtles. They will then protect the nest with a wire exclosure cage. In late summer they return to the nest to collect eggs which are transported to Woodland Park and Oregon Zoos where they will grow in safety.

“Due to the fact that wild turtles don’t feed in the winter, they become active in the ponds at a very small size and are easily predated on. Head-started turtles are fed all year and so when released, are less likely to be predated on just because of their larger size,” said Kevin Murphy, an animal curator at Woodland Park Zoo. “Once the turtles reach a suitable size to escape the mouths of invasive predatory bullfrogs, about 2 ounces, we return them to protected sites in their natural range where they’re monitored by biologists.”

A western pond turtle being released

Photo Credit: Jeremy Dwyer-Lindgren/Woodland Park Zoo

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In the wild western pond turtles range from the Puget Sound area of Washington through western Oregon and California to Baja California. They can survive up to 50 years but most hatchlings will not reach adulthood and as such populations are slow to recover.

In 1990 their population had dropped as low as 150 individuals across just two individual populations. They were nearing extinction due to predation by bullfrogs, disease, habitat loss and a respiratory disease.

Since the head start program began in 1991 over 2,300 turtles have been returned to the wild. 800-1,000 of these turtles survive today and continue to thrive.

A western pond turtle being checked prior to release

Photo Credit: Jeremy Dwyer-Lindgren/Woodland Park Zoo

“Woodland Park Zoo and other partners have been essential in the key stage of raising the turtles and helping to bring this species back from the brink,” said Hannah Anderson, WDFW Diversity Division Manager. “With invasive species, low reproductive rates, and real challenges from habitat loss and disease, it is good to know caring organizations like Woodland Park Zoo are working alongside us through their head start program to bring this once prevalent species back to Puget Sound and other areas around Washington.”

Unfortunately the western pond turtle is not out of the woods just yet. Recently a shell disease has been discovered in the population. This disease currently affects 80% of the population. Chicago’s Shedd Aquarium and the University of Illinois at Urbana-Champaign have joined the recovery efforts and are looking to determine the origin of this disease and any environmental factors which may affect it.

Woodland Park Zoo, Oregon Zoo and the WDFW are working to ensure this disease does not send the species extinct. This includes providing over-winter care for the affected turtles giving them a chance to heal before returning to the wild in Spring.