How do Risso’s dolphins get white scratches?

How do Risso's dolphins get white scratches?

Last show’s winner was Izzy who correctly stated that a “wholphin” is a hybrid cross between a false killer whale and a bottlenose dolphin. Now, for this week’s quiz: where do the white scratches seen on the skin of Risso’s dolphins come from? Think you know the answer? Surf on over to and click on Dolphin Quiz – leave your answer in the comments section. Winners will randomly be chosen from the correct answers, and will be announced on next week’s show. 

Risso's Dolphin

Image from David Hofman's website