In the 1950s, California wildlife authorities used to fly over remote lakes and creeks in Yosemite National Park and deliver precious cargo: hatchery-raised trout.
The policy was great for fishing enthusiasts. But for the yellow-legged frogs that shared those waters, the arrival of hungry trout was a disaster.
These days, wildlife officials are using helicopters to transport the fist-sized frogs to some of the very same waters, which are now being rid of non-native trout.
It’s part of a strategy that has helped the frog population grow at a rate of 11% a year since 1991, according to a