As a California herpetologist and western pond turtle skilled, I typically joke about how I’ve the simplest job: figuring out the one turtle species native to California. In California—and alongside the higher Pacific Coast, for probably the most half—western pond turtles are the one native freshwater turtle species you’re supposed to come across within the wild. However laypersons {and professional} scientists alike are usually confounded when attempting to tell apart them from any variety of non-native pond sliders (Trachemys spp.) that discover their means into city waterways and past, by way of the pet commerce.
Initially of the pandemic, I set myself the objective of serving to determine each turtle remark reported in California, Oregon, and Washington on iNaturalist, the biodiversity database powered by public observations, as a option to hone my identification abilities and contribute my experience to the group. iNaturalist’s picture recognition software program might be spot-on, nevertheless it isn’t good, and this—paired with incorrect identifications contributed by the well-meaning public—can muddy the waters on the subject of correctly figuring out turtles in California.
That is all of the extra necessary immediately as a result of western pond turtles at the moment are candidates for the federal endangered species checklist, and the state and federal businesses have turned to iNaturalist as a key useful resource in establishing the place western pond turtles are and are usually not.
An excellent 12 months into the pandemic and my project, I crossed paths with Brian Acord, a biologist with the California Division of Fish and Wildlife’s California Pure Variety Database (CNDDB). He had been set the identical process of figuring out and verifying California turtle observations in iNaturalist. Collectively, we realized that the general public and professionals alike had been usually confounded by “melanistic” pond sliders—particularly grownup male Trachemys turtles. Their markings can darken as they age, masking their vibrant yellows and reds, and revealing speckles and marbling towards a matte background that extra intently resembles western pond turtles. (I’ve highlighted some examples of this on iNaturalist.org.)
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To handle this misidentification problem, Acord and I, together with Rachel Freund and Annie Chang, developed a photo-illustrated information relevant up and down the West Coast that identifies 11 necessary diagnostic traits, together with two key traits (the form and association of two completely different “scutes,” the plates on a turtle’s prime shell) that any layperson can hold their hat on if they will get a superb have a look at the turtle in query from anyone angle. In fact, nothing beats a transparent, sharp, close-up picture. In lieu of a Bay Nature-quality cowl picture, the information ought to assist present sufficient clues for the general public to make a easy, educated resolution: native turtle, or not native turtle. Easy, positive, however extremely necessary for company employees and land managers working to preserve the species.
Diagnostic traits apart, now we have just a few extra phrases of knowledge:
• Don’t assume it’s a slider since you are in an city setting;
• Don’t assume it’s a native turtle since you are in a pure space;
• Don’t assume it’s both species as a result of the opposite has by no means been reported there earlier than.
These might be context clues, however not the only foundation of an identification.
To study extra about distinguishing western pond turtles from non-native sliders, or in regards to the “melanism” in pond sliders that obscures their stunning markings, try our photo-illustrated information under. I additionally go right into a bit extra element on the physiological particulars in this put up on iNaturalist.
Your Bay Space Turtle Information
Printable model right here: Information to distinguishing California freshwater turtles
