Hooded Seals get SatNav, too

Southern Elephant seals have been known for a while to be perfect "vessels of opportunity" for oceanographic as well as biological research. More recently, narwhals were also discovered as suitable carriers of oceanographic data loggers, which communicate their collected data through the ARGOS satellite system, and were aptly titled oceanographic unicorns.

Now hooded seals join the club, as they now also get to carry loggers and sat transponders on their heads:



According to the researchers in charge, these SRDLs (Satellite-Relay Data Loggers) weigh about 400 g, and have negligible impact on the seals. They represent a maximum of 2% of the body weight of the animal carrying them, which range in size from 30 kg – 1.5 tonnes.