Species #22: Western pond turtle (Actinemys marmorata)
Location: Riverside County, California
Date: 6 May 2017
Species #23: Mojave desert tortoise (Gopherus agassizii)
Location: Desert Tortoise Natural Area (California City, California)
Date: 7 May 2017
Post by George L. Heinrich
During my return flight from Los Angeles to Tampa, I found myself reminiscing about the three days that I had just spent searching for wild turtles in southern California. Although I was born in Bellflower in Los Angeles County, my parents relocated our family to Connecticut just before my first birthday. While growing up in southern New England, I had the opportunity to watch spotted turtles and wood turtles in the local woods, and to develop my love for wild chelonians and their associated habitats. I had returned to California twice for turtle conferences many years back, but this recent trip was the first opportunity to solely focus on exploring natural areas of the Golden State. It was a long way to travel for two species, but both were needed to advance the species count for The Big Turtle Year to 23.
The Big Turtle Year is a large and complex project with many moving parts. The strategy that Tim Walsh and I have used to organize this year-long conservation education initiative is to have turtle biologists and conservationists from throughout the country assist with logistics for their respective states and regions. I had asked our old friend, Michael Bargeron (California Turtle and Tortoise Society; www.turtlesociety.org), to be responsible for planning and to address logistical concerns in order to assure that we would see both the Mojave desert tortoise (Gopherus agassizii) and western pond turtle (Actinemys marmorata) in California. It was clear that Michael had put the required time into the task as everything ran as smooth as glass. Just like with Texas, we had picked the right person for the job.
Upon arrival in Los Angeles, Michael took me to visit Polliwog Park in Manhattan Beach where I had the opportunity see hundreds of non-native red eared sliders (Trachemys scripta elegans). After the novelty of having a pet turtle diminishes, people often release them into local ponds where they may compete for resources with native species. Thanks to the pet trade, this invasive species can be seen well outside of its natural range and in many countries around the world. See The Big Turtle Year Update #5 written by Tim Walsh for more information on red-eared sliders.
The next day, Diane Brouhard and Lydia Salinas (two more longtime friends and members of the California Turtle and Tortoise Society) joined Michael and me to search for western pond turtles with Jonathon Reinig of the Riverside County Regional Park and Open-Space District (www.wrc-rca.org). The District's work focuses on managing public-owned lands which support many state and federally listed species in this rapidly developing county located southeast of Los Angeles. We visited four sites each quite different in appearance and known to support western pond turtles. Each location exhibited signs of human impacts, both past (agricultural land) and present (adjacent development). Although the first site was the wildest in appearance, it was not there that we found species #22, rather it was on public-owned land located near the entrance to a subdivision and adjacent to a major road. Our single sighting of a western pond turtle on that day was of an adult basking at the base of dead cattails.
This medium-sized emydid turtle occurs in Washington, Oregon, and California, and barely enters Mexico (northern Baja California). It appears to be extirpated in both Nevada and Canada. Western pond turtles are the only remaining freshwater turtle species native to California. Formerly in the genus Clemmys, the western pond turtle is a listed species in all states within its U.S. range (Species of Special Concern in California and federally listed as a Species of Concern). Western pond turtle populations are in serious decline and in need of continued strategic conservation efforts. Anthropogenic threats, including habitat loss, agricultural activities, overgrazing, highway mortality, introduced predators, and illegal commercial exploitation for food have all impacted this Pacific Coast turtle. In addition, shell disease has become an issue in some parts of its range and of significant concern is the tremendous impact that lengthy droughts have had on this species.
Michael, Diane, and I traveled to Mojave, California late that evening so that we could take advantage of the cooler morning hours while searching for Mojave desert tortoises at the Desert Tortoise Natural Area (www.tortoise-tracks.org) in nearby California City on the following day. This conservation land was established in 1979 and protects about 12 square miles of desert habitat, and has long been on my list of places to visit. One of four tortoise species that occur in the United States, it can be found north and west of the Colorado River in California, Nevada, Utah, and Arizona. The species also occurs in Mexico. It is a ‘protected’ species in all states within its U.S. range and is federally listed as Threatened.
The temperature at 7:15 the next morning was a cool 43.7 degrees F, not ideal for finding reptiles. However, by 11:45 am the temperature had risen to 60 degrees F and we found our first tortoise right along the side of the trail. A couple of hours later we located a second tortoise sitting in the shade under a bush. Three species of lizards were active throughout our visit: desert horned lizard (Phrynosoma platyrhinos), western whiptail lizard (Aspidocelis tigris), and side-blotched lizard (Uta stansburiana). To learn more about desert tortoises, please visit the Desert Tortoise Council’s website at www.deserttortoise.org.
Our third day in the field found Michael, Diane, Lydia, and I meeting up with Rosi Dagit, Senior Conservation Biologist with the Resource Conservation District of the Santa Monica Mountains (www.rcdsmm.org). Rosi is a fascinating biologist who studies penguins, southern steelhead trout, and western pond turtles. I first met Rosi while visiting her study site back in 2003 and I was looking forward to spending another day in the field with her. It was wonderful hiking on the same trails as during my earlier visit, enjoying a magnificent landscape, seeing endangered plants, and most of all documenting species #23 (three western pond turtles basking in a pile of tree limbs over a pond in the distance). Later, back at her office, we had an opportunity to examine and photograph a couple of western pond turtles that were being rehabilitated after a predator attack, as well as several shells from predated turtles. Water issues are of concern for many U.S. species and the western pond turtle is no exception. The long drought in California has had a severe impact on these imperiled turtles; with dropping water levels they can become desiccated in the drying mud and also be exposed to predators. To learn more about this subject, please view Rosi’s article: click here.
Despite cooler than normal temperatures for this time of year, we still found the two species for which I had traveled across the country. This was a great trip and provided a very welcome opportunity to reconnect with old friends. I will have wonderful memories of hiking in the Mojave Desert and the Santa Monica Mountains for many years to come.