An elephant is drinking out of a river when he spots a turtle asleep on a log. The elephant ambles over and kicks the unsuspecting turtle clear across the river.

'Why did you do that?' asks a passing giraffe.

'Because I recognised it as the same turtle that took a nip out of my trunk 47 years ago.'

'Wow, what a memory!' says the giraffe.

'Yes,' says the elephant. 'Turtle recall.'