Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet initiative has ...

It’s a sound somewhere between a hoarse car alarm and a braying donkey. Barely visible through the foliage from ground level, the source of the racket sits in the upper branches of a decades-old ...

Add Yahoo as a preferred source to see more of our stories on Google. Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, ...