Weddell Seals May Use Earth’s Magnetic Field As GPS
Antarctic seals whilst hunting, may make use of the Earth’s magnetic field which functions as a kind of natural GPS according to the results of a new study. Weddell seals are uniquely adapted biologically speaking to deep dive whilst hunting, but they also have an amazing ability to locate the breathing holes they need on the ice surface. Scientists have been perplexed by this amazing ability and have sought to find some answers.
First marine mammal with natural GPS
Scientists researching these seals believe they are able to achieve this feat by using the magnetic field of the Earth as a Global Positioning System, which if true would represent the first evidence of such ability in a mammal that spends most of its time in the ocean. Terrie Williams and Randall Davis of the University of California Santa Cruz have been studying how Weddell seals behave for decades along with another colleague Lee Fuiman of the University of Texas.
The theory dates back to the 90’s
The hypothesis that these seals have the ability to track magnetic lines originates as far back as the 1990’s, when the researchers first began working together in Antarctica. Dr Fuiman says he was surprised by data produced from the onset of their study which showed the seals returning to the same dive holes with amazing precision, time and time again. This prompted the team to start thinking about what causes the phenomenon.
The data is still not conclusive
The researchers say that whilst the behaviour from drive profiles is very intriguing, the data is far from conclusive. The researchers will continue to study Weddell seals to determine whether the seals, like homing pigeons, make use of magnetic lines to make their way back home. For the next three years, the team will work with a handful of Weddell seals. All the seals that are being studied will be kitted out with a video and data recorder. The seals will then be released into three different areas in McMurdo Sound over the course of couple of weeks.
The theory will be put to the test
The area was chosen because the researchers have already precisely mapped the magnetic field. The research team is expecting there to be changes in behaviour when the seals are in a different magnetic field. The researchers will then compare the dive profiles of the video and data recorders with the magnetic anomaly maps of McMurdo Sound which they believe should provide some answers. If the theory turns out to be correct, it will be truly astonishing.
