But the whales kept swimming into a small, shallow bay with large boulders, where at least one removed a transmitter by rubbing against the rocks. Several subsequent papers have also noted the behavior, usually concluding the whales were using the rocks to rest. But Ms. Fortune noticed that large pieces of skin were peeling off some of the whales. Overhead footage of the whales taken by drones in 2016 — part of another study tracking the whales’ summer feeding habits — reveals that the animals are using the large rocks to rub dead skin off their bodies. “We could clearly see these whales clustered around these boulders taking turns sloughing off skins.”PhotoBesides solving a centuries-old mystery, the findings confirm long-held suspicions about how bowhead whales molt.

Source: New York Times November 22, 2017 18:56 UTC