Gibbon on Instagram: "What do gibbons and Groot have in common? They both use what’s called context-specific calls: very slight variations in a basic call that are used to mean different things depending on the situation. Gibbons use a “hoo” call for quiet communication with nearby family members or, more rarely, neighbours. Depending on how it’s produced, a call can mean: “I’ve spotted some good food” (food hoo) “I’ve spotted a raptor” (potential predator) “I’ve spotted a big cat” (another pote