Killer Whales Confirmed to Migrate ... for Spa Treatment

Some orcas could travel as much as 10,000 kilometres to shed their skin in the warm waters off the coast of Brazil.

A team of marine biologists has confirmed for the first time that some killer whales migrate some 10,000 kilometres across the Atlantic Ocean, and not for the typical reasons of chasing food or mating. Instead, the team believes, they travel all that distance to exfoliate their skin. Twelve killer whales were fitted with tracking tags off the coast of Antarctica in 2009, and while six tags fell off, the paths of the other six whales showed that they travelled from the southern fringes of the Atlantic to the coast of Brazil and back again, with one whale making the trek in just 42 days. But their trips also had some peculiar features that aren't seen in other animals' migratory habits, such as that the whales' departure times were scattered across three months, they swam individually, didn't breed when they got to their destination, and didn't appear to be chasing any prey. That led the biologists to conclude that they swam to the warmer waters so that they could shed a layer of their skin encrusted with algae without exposing themselves to the freezing - and thus potentially dangerous – temperature around the South Pole. This migration has only been recorded among the orcas of the Antarctic, as populations that make their homes in warmer waters probably wouldn't have to travel halfway across an ocean for what amounts to an aquatic version of a day at the spa.