Why do giraffes have purple tongues?

If you’ve ever been lucky enough to be licked by a giraffe, you’ll notice that their 50cm-long tongues can appear purple, bluish or almost black in colour. This is due to the density of dark ‘melanin’ colour pigments in them. There’s still no definitive explanation for this, but the leading theory is that the melanin provides extra UV protection, preventing their delicate tongues from getting sunburnt as they feed up high.