Orcas Keeping up Appearances

Ever wondered how orcas always look so immaculate in their black and white tuxedos? Well, some have recently been observed mutually grooming each other and using selected fronds of kelp to do it. Orcas are using tools.

A pod of 73 orcas, which live in the southern part of the Salish Sea -- a section of the Pacific Ocean bordering Washington state and the province of British Columbia -- have been observed biting off short sections of bull kelp and rolling the stems between their bodies, possibly to remove dead skin or parasites.

According to a study published in Current Biology, this behavior was widespread within the group. Larger whales have been previously observed with kelp draped over their bodies. The behavior, witnessed for the first time last year, differs because the kelp is selected, trimmed, and manipulated between two whales working together.