CROAK is a fictional story with a scientific basis. Here's how to separate fact from fiction:

The setting, characters and events are fictitious, and any resemblance to any person, living or dead, is purely coincidental.

The frog species Rana viridiana is fictitious. It is modeled on Rana aurora, the red-legged frog. Rana aurora was once found throughout California; it's the frog Mark Twain immortalized in his story "The Celebrated Jumping Frog of Calaveras County." Rana aurora is now in decline over much of its range, possibly due to habitat fragmentation and competitive pressure from an invasive species, the Eastern bullfrog.

For story reasons, we simplified the mystery puzzle, and compressed the time line. In real life, an animal population declines for several reasons, and more slowly than is presented here.