Western Pond Turtle By Bob Garrison
Outdoor California -- May/June 1998 Nothing represents the approaching days of summer better than a line of western pond turtles basking in the sun atop an old snag. These cold-blooded reptiles spend much of their day regulating their body temperature. In cool weather, they leave the water to bask in the sun at favorite basking sites. During hot weather, they float in the cool water. The turtles spend most of their lives in the water, but need well-drained silty soil to lay their eggs. The female will travel over 400 meters to find suitable nesting sites in upland areas away from the water. In late spring, one to 13 eggs are laid in a shallow hole which is then covered with dirt. Nests are highly susceptible to predators as well as to trampling by cattle or people. The western pond turtle is the only native turtle that lives in California. It ranges from Washington to Baja California. Once a common site along most low elevation ponds and
streams, the western pond turtle is quietly disappearing from the California
landscape. Over 90 percent of the freshwater ponds, marshes and year-round
streams where the turtles once lived have been drained, diverted or developed.
Where the turtles can still be found, many populations no longer produce
offspring, the result of disturbed nesting grounds and the predation of
young turtles by non-native bullfrogs and black bass. With a life
span of over 40 years, the presence of turtles may be a false indication
that populations are healthy. As a result, western pond turtles have
been classified as a species of special concern and require careful monitoring.
Finding western pond turtles can be a challenge. Beyond their declining population, western pond turtles look similar to many types of non-native turtles that now live in California's waterways. The turtles commonly seen in ponds are most likely painted turtles, slider or spiny softshell turtles. These mid-west and east coast species were once sold in pet shops and many were released in ponds when no longer wanted as a pet. When you spot a turtle look at its head.
Western pond turtles have a blunt nose and black spots
or blotches on the light-colored head. Sliders and painted turtles
have similar shaped heads but have light stripes or whorls on a dark head.
The spiny softshell turtle has a pointed nose.
As a wildlife viewer, you can help the turtles a number
of ways. First, watch from a distance. Stay back so you don't
scare the turtles from their basking areas. Do not create a path
to the water's edge. Raccoons, skunks, cats and other predators will
use your trail to hunt for nest sites. Keep track of the locations
and numbers of western pond turtles you observe. In particular, watch
for young turtles to determine if the population is successfully breeding.
Keep land managers informed of your observations.
NOTE: Two Western Pond Turtles were sighted at the nature preserve in the month of May, 2001. Due to the lack of water at the preserve, the turtles are on the move to find suitable nesting sites. It is a relief to finally get some water as of May 14th. We hope Kaweah Oaks Preserve will get more consideration from the irrigation districts in the future. Images are of a mature Western Pond Turtle found on Hwy. 198 and Johnson's Slough at Kaweah Oaks Preserve on May 2, 2001. The turtle had suffered severe injuries and did not survive. Dennis Haines, of the Tulare County Agricultural Commissoner's Office, identified this injured turtle as a Western Pond Turtle before it expired. Sources: A Field Guide to Western Reptiles and Amphibians, Stebbins
This article is used with permission of the author, Bob Garrison, who is no longer with the Department of Fish and Game. Articles appearing in OUTDOOR CALIFORNIA! may not be reprinted without prior permission. Photocopying for classroom use is permitted. |
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