by Ben Schleifer
When I go on a hike, I always hope to see a rare species of animal. Usually, these evasive animals can hear me coming from far away and avoid my heavy footfall, but on those seldom occasions I do see one, I feel like I have experienced something special. Most people go their whole lives without seeing a bear, or a moose, or a bald eagle in the wild, and knowing I have seen those makes an exhausting outdoor trip seem worthwhile. Still, you do not have to travel on a tiring journey to see a rare species of animal. There are many in and around Marin, and if you have ever been to the reservoirs of the Marin Municipal Water District you might have seen one or two. The Actinemys marmorata, or western pond turtle, is one of those subtle rare species that might have escaped your notice.
Western pond turtle at Carson Falls
(photo courtesy of Lorri Gong)
These brown-to-black turtles are found in ponds and lakes all over western North America. Their only truly distinctive characteristic is a motley yellow and brown neck, so unless they are basking on a warm spring day, they are not easy to identify. Still, the western pond turtle is the only native freshwater turtle in California, and they are species in decline. They are recognized as a vulnerable species in California. Their dwindling numbers are in part due to loss of habitat and competition with other, invasive turtles like the red-eared slider. Both western pond turtles and red-eared sliders are found on the reservoirs of MMWD, which has been implementing practices to help protect our native California species.
Scientists at MMWD have been monitoring the turtle populations of both species since 2003. In 2009 an AmeriCorps intern suggested the district set up a program to monitor these turtles with citizen scientists—an idea that has now been implemented for the last three springs. AmeriCorps interns at MMWD, like myself, train volunteers in turtle identification and data collection. Then these volunteers walk around the beautiful lakes of MMWD collecting observations. We have Turtle Observers ranging from seven years of age to seventy years of age, and they are all contributing to our knowledge about these turtles on the watershed.
A native western pond turtle flanked by two non-native red-eared sliders at Phoenix Lake
(photo courtesy of Lorri Gong)
In 2012, our Turtle Observers made 41 visits for 76 hours of observations at the MMWD reservoirs. They made 327 individual turtle observations, and from these observations, we estimated the reservoirs have seven western pond turtles and 27 non-natives. These numbers will help the scientists at MMWD know where to focus their turtle-trapping efforts to remove the invasive turtles. The Turtle Observers also informed countless hikers and bike riders about the native and non-native turtles, and shared with some lucky visitors the experience of seeing a rare species.
We train new Turtle Observers each spring. If you or a young budding scientist you know would like to take part in the amazing outdoor field science of turtle observing, please contact MMWD at volunteerprogram@marinwater.org.
If you would like to see how this year’s numbers compare to 2010 and 2011, click here.
I would like to personally thank all the Turtle Observers who turned in turtle report data sheets. It is a testament to what these folks value that they are willing to give their time to protecting and monitoring this native species. Thank you so much to Colin Lester, Sean Tipett, Kathy Tama, Shelly Hauser, Laurel Kelly, Matthew Brod Naeve, Richard Alden Feldon, Marge Gibbs, Eliza and Shelly Peppel, and Lorri Gong.
Think Blue Marin 