Here's a one-minute breakdown of how native northwestern pond turtles returned to Yosemite – and why it's important:
- American bullfrogs were introduced to western USA in the 20th century. Since then, they have become a significant threat to wildlife in Yosemite National Park, among other places, preying on native species such as turtles, other frog species and small birds.
- The northwestern pond turtle (Actinemys marmorata), California’s only native freshwater turtle, saw its population diminish due, in part, to bullfrog predation.
- The northwestern pond turtle is important because it feeds on a variety of plants, insects and carrion, helping break down organic material and redistribute nutrients, which in turn ensures the ongoing health of aquatic environments in Yosemite.
- A new study, which ran from 2016 to 2022, has revealed that areas without bullfrogs had up to 100 times more northwestern pond turtles, including juveniles, compared to bullfrog-infested sites.
- Following bullfrog removal efforts, which were completed in 2019, several native species – including the northwestern pond turtle – have started to repopulate the park’s waterways.
- The success in Yosemite suggests that targeted removal of invasive species can be a vital strategy in restoring native wildlife populations.
Want to find out more? Read the full article about how scientists helped northwestern pond turtles return to Yosemite National Park.
Main image: scientists hike into Yosemite National Park. Credit: Sidney Woodruff/UC Davis
