Western Pond Turtle- Main Page
Frank Slavens, Curator of Reptiles, Woodland Park Zoological Gardens, Seattle, Washington
Great things can be created out of disasters, and this is the story of a very successful project to help restore the western pond turtle to the state of Washington. Surveys from 1985 to 1990 confirmed the species had declined throughout the natural range in the state. Whereas the western pond turtle had been described as "common" in the Puget Sound area, it was now virtually extinct. The only remaining wild populations were at two sites in the Columbia Gorge, with perhaps 150-200 turtles between them, and they were in trouble. In 1990, a researcher, working for the Washington Department of Wildlife, was surveying those populations and witnessed the devastating disease that killed an estimated 25% of the turtles. Natural recruitment had practically ceased to exist. If something could not be done soon to help the species, it would be gone from the state of Washington in 25 years.
Frank and I met Dan Holland, the researcher, on June 10, 1990, the same day he found the first dead turtle. We discussed his work and how zoos can be active in conservation projects. Little did we know on that day, that within one month, at least 40 sick and dying turtles would find their way to Woodland Park Zoo for medical treatment. A newly constructed building was designated quarantine for the turtles and slowly most of them died. Only thirteen of the turtles survived. Tissue samples were sent across the state and the country to be analyzed for identification of the disease, resulting in no firm diagnosis. It attacked the respiratory system and killed quickly. We were all unsure about the future of the wild populations or the remaining individuals at the zoo.
One hopeful situation did exist. Dan and his crew had located six turtle nests and had marked them with exclosures. We would have hatchling turtles in September, and they could be head-started and released. The biggest problem was finding another site for the recovered turtles before bringing in the babies. From September 1990 until February 1991, the hatchlings were kept in our basement. Then, the Department of Wildlife refitted an old pheasant hatchery into a turtle holding facility. The adults could be moved there and the hatchlings to the zoo.
At this point, a strong bond had been created between the Washington Department of Wildlife, the Woodland Park Zoo and the Slavens. This consortium would be the basis for all subsequent efforts to save the western pond turtle. We still were not sure how best to proceed. We were able to determine many of the causes of the turtle's decline. In western Washington, habitat destruction in the forms of draining of wetlands and lakeside houses were the major factor. Many turtles had been taken for the restaurant industry and some as pets. The prospect of recovery was grim. In eastern Washington, however, there was hope. The greatest cause of decline, since the little boys in the neighborhood grew up and stopped shooting the turtles, was introduced bullfrogs and fish. Seining fish out of one lake and bullfrog whacking were attempted to increase natural recruitment. The fish and the frogs recovered practically overnight. The memory of the disease was still fresh and we were still very cautious about working too aggressively with the wild turtles.
On August 19, 1991, the remaining survivors of the disease were released into the lake with the smallest population of turtles. Eight were transmittered and we learned "on the job" how to locate turtles with telemetry. They were monitored intensively for a month for reassurance that they would be fine. This month also brought important information about aestivation during hot summers. Several of the turtles moved out of the water, up onto wooded hillsides and spent days, weeks, or in one case, months under logs. All were back in the water by spring. A better understanding of the natural history of the species would help us choose a course to the recovery. On the same day, 14 of the head-started turtles, having attained a suitable size to avoid predation by large-mouth bass and American bullfrogs were also released into other ponds. The remaining nine would have to wait another year.
During the remainder of 1991 and through 1993, we continued to survey the sites, trap the lake to check on the released turtles, watch for nesting females, and devote late nights to killing bullfrogs. We still believed that eliminating as many bullfrogs as possible would help recruitment of hatchling turtles. There were too many bullfrogs. Our cautious attack of the problems would have to be more aggressive if the turtles were to survive.
This attack included many different aspects. The Washington Department of Wildlife purchased three parcels of land, a total of 165 acres, which surround the two sites in Klickitat County. The Nature Conservancy has assisted in some of these purchases. Adjacent property is now in the process of being added to the site. Negotiations are ongoing with landowners in Skamania County to purchase the property surrounding the turtle ponds in that area. Protection of these sites is paramount and our neighbors and former landowners are watchful when we cannot be there. The western pond turtle was also listed as an Endangered Species in the state in 1993.
Beginning in 1994 and continuing until today, we have engaged a formidable force of volunteers to trap turtles each spring, transmitter females, and monitor the females through the nesting season. These volunteers are not professional biologists; they are people from many walks of life sharing a love for turtles and a dedication to the project. They are willing to brave cold, wet, hot, and windy weather. They are willing to check a turtle at 0500 or 2300 or both, depending on the turtle. They are willing to sleep in tents pitched in old barns, eat lots of bologna sandwiches, encounter rattlesnakes, and smash bullfrogs. They are very special people. Visual surveys continue to be an important tool to estimating the populations in each pond and the use of temporal ponds in the spring. These counts are most effective at the end of April when all of the turtles are out of hibernation and beginning to eat.
Trapping begins April 1 and continues until May 15, the traps being checked twice daily. All turtles are weighed, measured and checked for any medical problems. Any unmarked turtles are issued WDFW numbers, which are filed into the marginal scutes. All data is recorded in a notebook for that year and new data can be compared to previous records available in another notebook. Our database now contains records for 577 pond turtles. Changes in weights, measurements, scars and locations can be compared before the turtle is released. Adult females are fitted with transmitters that are epoxied to their carapaces. All turtles are released into the ponds from which they were trapped within hours of capture. The object is to traumatize the turtle as little as possible. Any bullfrogs captured are destroyed.
Telemetry begins as soon as there is a female out with a transmitter. Her location is checked at least once a day until May 15, when the routine changes. At that point, all females are located every two hours from 0900 until 2100 every day until she has nested or until July 15. If a female is out overnight, she will be checked as early as 0500. Many females are also monitored for double clutching. The females at these sites have abundant to unlimited nesting habitat and will go out in all directions to nest. The nesting habitat is so abundant that in all the years of surveying and monitoring, not one predated nest has been found. The raccoons and skunks can find easier meals. The nests, when located, are checked for eggs. Most nests then have temperature and humidity sensors buried next to the egg chamber and everything is covered with an exclosure for its protection and to help us find it at hatching time. At that time, another crew, the former landowners, check nests twice each day in the case of fall emergence. When the eggs have hatched, whether the hatchlings have emerged or not, the little turtles are collected and relocated to Woodland Park Zoo for head-starting. As of fall, 1999, the Oregon Zoo in Portland will also assist with our head-starting, allowing us to exceed our usual goal of 100 hatchlings per year. The field season ends when all the nests have been collected.
Our success has been dependent on our learning curve and the number of transmitters we have been able to activate each year. In 1994, we found one nest, and in 1995, only three. We were getting better. In 1996 we added a second site and more personnel, and found fifteen nests. In 1997 we found sixteen and in 1998, eighteen. We then, including the nests from 1990, had collected hatchlings from 59 nests resulting in 280 turtles that have been head-started and released. Eighteen nests have been identified in 1999, which will probably produce 75-100 hatchlings. Because hatching success is dependent on weather conditions, a cold and wet June can impact the development of the embryo and entire nests may fail to hatch. We now use the temperature and humidity sensors in most nests to try to establish the limits for successful hatching. This data is still being collected and will be analyzed sometime in the future. This information can also act as a guide for captive incubation of eggs.
Concurrently, with the fieldwork, the Woodland Park Zoo has been engaged in captive breeding of the species. Four turtles with western Washington genetics and a trio from Portland, Oregon have produced young for release in the Puget Sound area. Thirty hatchlings have been released into protected ponds south of Tacoma. The Oregon babies are being held aside for more genetic study to confirm that they are indeed compatible. Eastern Washington turtles have also been kept at the zoo and have produced 12 hatchlings, which have all been released. Before release, all the young turtles are implanted with transponders or PIT tags for future identification if the filed notches are somehow destroyed. The greatest amount of keeper time is spent caring for the young turtles from the captive breeding and the wild nests. The building they are kept in is quarantined from all other reptiles at the zoo and the keepers do not work other reptile areas. Veterinary assistance is available at all times.
You may be wondering how we are able to fund all this work. It is not easy and we do not always know from one year to the next if we will be able to continue doing everything at once. A successful project will produce more contributors. The first budget came from the Washington Department of Wildlife Aquatic Lands Enhancement Account, which specifically supports the work of volunteers and we continue to receive these funds. Volunteers receive compensation for their mileage to the turtle ponds. It also has purchased traps, transmitters, and other equipment. The Woodland Park Zoo donates keeper time as a match for other funds and provides transponders and veterinary care. The Center for Wildlife Conservation, a local consortium has generously purchased much of our equipment. The Woodland Park Zoological Society Conservation Committee is becoming our largest contributor, both with their money and help in writing grant proposals. The U.S. Fish & Wildlife Service has, through the Endangered Species Act Section 6 and also the Partnerships for Wildlife Program contributed matching funds for the project. The American Zoo and Aquarium Association Conservation Endowment Fund has made the project a year-round endeavor and is spearheading education efforts at the Woodland Park Zoo. The U.S. Forest Service purchased some transmitters for us in 1996. Western Aquatic Turtle Education & Research has helped smooth over the purchases of unbudgeted items needed on the spur of the moment and such luxuries as electricity and a Sanican. We have produced and sell T-shirts to keep that fund healthy.
This brings us to the future of the project. By the end of 1999, the Washington State Recovery Plan for the Western Pond Turtle should be complete. Fieldwork will need to continue for many years to achieve the goals in the recovery plan. New release sites are already being scouted and evaluated for their potential to support western pond turtles. Other zoos in the area are interested in doing head-starting and captive breeding. Bullfrogs will continue to be whacked and the egg masses destroyed. Surveys will continue in the Puget Sound area to collect any remaining western pond turtles for captive breeding. Educational programs are in the development stages and will begin soon. Full recovery is a slow process with a species that naturally has low recruitment. The commitment has been made by The Washington Department of Fish & Wildlife, the Woodland Park Zoo, and a stubborn group of volunteers to see it through and hopefully, within our lifetime, we will succeed.
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Pages first went up in October 1995.
Copyright © 1996, 1997, 1998,1999, 2000, 2001, 2002, 2003 Frank Slavens