Under the skin of a marine mammal

This Weddell seal emerging from the pack ice is not a spy but a lactating female equipped with a miniature sonar. Attached to the animal’s fur, this device enables biologists to track its movements during its breath-hold dives in Antarctic coastal waters. The sonar also records the seal’s head and jaw movements as it hunts. Analysis of this data should help scientists to improve their understanding of the feeding behaviour of female Weddell seals during the critical lactation period.