TIL Kelly, a dolphin, was rewarded with fish by her trainers for bringing them litter and dead gulls to clean her pool. She began hiding fish under a rock in her pool and used them to lure gulls, which she then brought to her trainers to receive more fish. She even taught her calf the same strategy.

http://www.theguardian.com/science/2003/jul/03/research.science
#til #todayilearned
https://www.reddit.com/r/todayilearned/comments/1aoxzja/til_kelly_a_dolphin_was_rewarded_with_fish_by_her/