The numbers of the Mountain Yellow-legged Frogs have dwindled over the past 40 years due to numerous reasons such as predators, food supply, and habitat encroachment.
Over 10 years ago, the San Diego Zoo began a program to improve those numbers and restore the Mountain Yellow-legged Frogs to much higher population numbers.
The breeding program has become quite successful and they are hoping to see signs of success soon.
View the whole story here: https://idyllwildtowncrier.com/2019/09/24/san-diego-zoo-working-to-restore-mountain-yellow-legged-frogs-to-their-mountain-habitat/