Two sea lions, two fur seals, and a paddle: the hearing test that could protect an endangered species

At Sydney's Taronga Zoo, four marine mammals learned a new game: hear a tone, press the paddle, earn a fish. Curtin University and Taronga researchers ran the first-ever hearing tests on Australian sea lions and long-nosed fur seals, discovering both species hear best around 3.2 kilohertz — the first detailed baseline for either animal. Published in two peer-reviewed journals, the work matters most for the endangered Australian sea lion, down to about 12,000 animals, which depends on hearing to communicate, find food, navigate and sense danger. Next, the team wants to learn how the animals hear underwater, where ship and construction noise is growing.