A healthy population of red-legged frogs is hopping in Yosemite National Park, helped by a reintroduction program with the San Francisco Zoo.
The San Francisco Examiner reports that the zoo on Monday released the last of more than 1,000 red-legged frogs into the park as part of a four-year effort to reintroduce the once-threatened species.
The red-legged frog population began declining 50 years ago after the introduction of non-native bullfrogs, exacerbated by increasing water drainage and raccoons.
The zoo has been raising the red-legged frogs and releasing them into the park over the past two years. Zoo data shows the frogs in the wild have survived and reproduced.
Ecologists this spring found clusters of eggs in meadows and ponds, proof of the first breeding in the park by the frogs.