This is a Red-eared Slider turtle seen at Delta Ponds. They are 'slowly' moving in and we see more and more of them there. The Pond Turtle is the native species and seem to be losing out to this newer resident.

About the Red-eared Slider: "It is the most popular pet turtle in the United States and is also popular as a pet in the rest of the world.[2] It has, therefore, become the most commonly traded turtle in the world."

"It is native to the southern United States and northern Mexico, but has become established in other places because of pet releases, and has become an invasive species in many areas, where it outcompetes native species. The red-eared slider is included in the list of the world's 100 most invasive species published by the IUCN."

From Wikipedia: https://en.wikipedia.org/wiki/Red-eared_slider