Turtle Tracks

From October, 2009 Newsletter

by Caroline Chan, Intern

 

The signal was faint but rapid and seemed to be emanating from somewhere upstream. With a radio antenna held out in front of me, I continued along the path until the signal became stronger, indicating that I was heading in the right direction.  Eventually, I stopped and pulled out my binoculars to scan a pile of woody debris located in a deep pool near the edge of the stream.

Finally, I spotted it!  It was an adult western pond turtle basking on a log near the bank.  The funny bump on top of its shell was actually a radio transmitter that had been attached one year prior as part of a radio-telemetry study of turtles at a coastal stream in the Santa Cruz Mountains.  As I moved toward it, the turtle quickly scurried into the water and the signal from its transmitter became noticeably slower, reflecting the cooler temperature of the water in the stream.

Later, that same day, I hiked over to check on a nearby turtle nest.  A wire enclosure had been placed around it when the nest was first discovered.  For ten months there was no sign of life.  Finally, in early April, the first hatchling dug its way to the surface of its flask shaped, underground burrow.  Although it was only the size of a quarter, it appeared to be a perfect miniature replica of its parents.  After being measured, weighed, marked and released, the hatchling quickly scampered off toward the nearby pond from which its mother had emerged the previous summer to lay her eggs.  As I watched it go, I wondered what was to become of this small, vulnerable reptile.As with so many other species today, western pond turtles are facing an increasingly uncertain future.  Habitat loss and alteration combined with population fragmentation and the increased pressures of competition and predation caused by the introduction of non-native species (such as bullfrogs which prey on young turtles), have all led to the decline of the turtle and its eventual listing as a “Species of Special Concern” in California.

Despite its dwindling numbers, cryptic coloration and tendency to rapidly dive off basking sites when disturbed, western pond turtles can still occasionally be spotted in the wild.  A great place to see them is at Waddell Creek in Santa Cruz County (17 miles north of Santa Cruz along Highway 1).  While there, be sure to stop by Turtle Pond and look for turtles basking amongst the tule and on logs in the open water.  If you’re lucky, perhaps you’ll even see some of the turtles that were tracked during the radio-telemetry study or, better yet, that little hatchling turtle who would just about be old enough to have a few hatchlings of its own!

References:

Tortoise and Freshwater Specialist GroupBury, R.B. and Germano, D.J. 2008. Actinemys marmorata (Baird and Girard 1852) – western pond turtle, Pacific pond turtle. In: Rhodin, A.G.J., Pritchard, P.C.H., van Dijk, P.P., Saumure, R.A., Buhlmann, K.A., and Iverson, J.B. (Eds.). Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian Research Monographs No. 5, pp. 001.1-001.9, doi:10.3854/crm.5.001.marmorata.v1.2008, http://www.iucn-tftsg.org/cbftt.

Smith, J.J., J. Abel and C.J. Davis (Chan). 1997.  Management plan for Waddell Creek lagoon and surrounding habitats.  Report to Calif. Dept. of Parks and Recreation, Big Basin, CA.  23pp.