Narwhals use their tusks

Narwhals use their tusks to bat around fish in first documented case of narwhal play.

Researchers have long debated what narwhals’ tusks are for, with some arguing that the long, spiralled tooth is a signal to potential mates, or that it could be a weapon, while others have argued it might be used to detect chemical changes in the ocean.? ? Now, researchers at Fisheries and Oceans Canada, a government department, have observed narwhals using their tusks to chase and hit Arctic char (Salvelinus alpinus) fish, both as a possible hunting technique but also potentially as a way to play. In one observation, an adult narwhal that was chasing a fish was soon joined by two other narwhals, who used their horns to track and mirror its movement for several minutes, without attempting to eat it, but apparently shepherding it along its path.? ? This behaviour appears to fulfil all the criteria for animal play, the researchers say, including having no obvious role in survival, as well as appearing to be spontaneous, repeated and exaggerated, and with the narwhal under no external stress. It’s unclear whether narwhals also hunt Arctic char for food, especially as they can eat squid or halibut in winter, which satisfies most of their energy needs.?