Turtle Observers

slider turtles and western ponds photo by sami kreling
Can you spot the western pond turtle on this log? Hint: It's the only one of its kind. All the others are non-native red-eared slider turtles. See the answer at the bottom of this page.
Volunteer Turtle Observers 
The western pond turtle, Actinemys marmorata, is a federally listed vulnerable species. These are the only fresh water turtles native to California, and they can be found around Phoenix, Lagunitas, and Alpine Lakes in the Mt. Tamalpais Watershed.

MMWD has enlisted the help of volunteers to protect this vulnerable animal by monitoring habitat conditions, recording their behavior, and educating the public during the spring when they are most vulnerable. Volunteers have collected valuable data on native and non-native turtles that is helping to direct the management of these species.
Did you know?
  • The western pond turtle has a life span of over 40 years.
  • During the winter, the turtles live in underground burrows in upland habitats.
  • In late spring, the females find a nesting site away from the water and lay eggs in a shallow hole that they cover with dirt. Nests and migrating turtles are highly susceptible to predators, unsuspecting hikers, and bicyclists.

"Ruffles the Turtle" by Turtle Observer Kathy Tama

Ruffles the Turtle by Kathy Tama 2014

Turtle Observer Program Results

How did we do in 2016?

We really appreciate all of the hard work our volunteers put in to monitoring the turtles and educating the public this season. Without their efforts none of this valuable data could be collected. During the 2016 season there were 29 new volunteers trained, 19 who participated in observations and five volunteers who returned from previous years. Our 24 volunteers observed for 84 total hours on 66 separate visits.


  • 170 western pond turtles (130 last year)
  • 458 red-eared sliders (607 last year)
  • 207 unidentified non-native turtles (75 last year)
  • 141 unknown turtles on the MMWD watershed (80 last year)
The 2016 population estimates for all lakes, based on single-day high counts, was 24 western pond turtles (29 last year) and 92 non-native turtles (176 last year).

Thank you to this year's volunteers: Dan, Dennis, Elizabeth, Frederic, Jeanine, Kathy, Kyle, Lamorna, Liza, Lorri, Marge, Michael O., Michael W., Penny, Phoebe, Quincy, Richard, Ryan, Sadie, Shelley, Steve, Tiger, Tyler, Victoria!

Areas Monitored

Turtle observations were recorded from late January through the last week of May.

  • The dam and shoreline of Lake Lagunitas
  • The shoreline of Alpine Lake along Bullfrog Trail
  • Alpine Lake below Bon Tempe Dam
  • The shoreline of Phoenix Lake on Phoenix Lake Trail and Shafter Grade Road

Non-Natives Removed

Trapping of non-native turtles was resumed in spring 2016 and took place in the Bullfrog Creek arm of Alpine Lake. Trapping was successful: staff removed 16 non-native turtles from the watershed this season.

Summary Report

For more details about the 2016 turtle program results, please see Turtle Observer Program Report 2016.

Addition Resources

A great article from the Point Reyes Light that delves into the plight of the turtle, and discusses conservation strategies.

Answer to question at top of page: The western pond turtle is the third one from the left in the top photo.

Remember: Please don't release your pet turtle in the wild!
Eric Turtle