Weddell SEAL plunk 100 of meters beneath the sea ice wall Antarctica . Having take in their target , or not , they need to get back to the atmosphere tight . Even their singular physiology ca n’t go without O forever . However , when dive under think ice find a jam to surface at is a matter of life and last .
The enigma of how they do this may soon be resolve . The favored theory is that they ’re using the Earth ’s charismatic landing field to lead them , and marine biologists have finally knead out how to test this .
Migratory birdsandpigeonsare jazz to use the planetary magnetic field on scales orders of magnitude large . However , if proved this will be the first time such a capability has been identified in a marine mammalian , potentially offering insight intomass giant strandings .
" These animals are doing a noteworthy amount of use all while on breath hold , " order Professor Terrie Williams of the University of California , Santa Cruz . " The ground a seal want to be effective is that they have a limited amount of oxygen onboard . The magic trick is conserving that ' scuba tank car ' on a dive . "
Williams has been working on the idea that Weddell seal habituate magnetic field line to orientate themselves since the belated 1990s . Dr Lee Fuiman of the University of Texas , has collaborated with Williams over that meter , and describes their reasoning from the first sentence they track the seal ' movements . " The animal always find its way back . It ’s like he have it away on the button where the golf hole was , " Fuiman say . " I could n’t figure out how they would do that . How did they know where they were by the clip they turned around ? "
In summer the seal might search for clean streaming through maw in the ice , but the sealing wax also dive during the long Antarctic winter when the sun never rises .
recognition : Peter Rejcek , NSF.Weddell SEAL are cute but lazy on land . However , under water they become noteworthy athletes .
magnetized bailiwick was an obvious hypothesis , so to try it the team mapped the magnetized field in unlike parts of McMurdo Sound . Filed lines are not consistent , owing to the influence of metallic element deposits . The team reasoned that , if their theory was ripe , as the seals moved into domain with different charismatic fields they should transfer their behaviour in some room .
With funding from the National Science Foundationthe squad have attached infrared video recorders and sensing element to the seals ' capitulum and send them in area with different magnetic fields . While promising , the data point they have pull together so far does not render a sufficient sample size to confirm the magnetic theory with certainty .
Next southern winter the squad are heading back to McMurdo to make headway a great sample distribution size , with the study conduct in dark so they can be trusted the seals are n’t “ cheating ” by using sun as might have been the character in the survey done so far . Directional hydrophones will test the theory of acoustical clues . It is forestall three years of research will be required to steadfastly establish the hypothesis .
Credit : Story by Peter Rejcek / Produced by Ralph Maestas / extra footage provided by Randall Davis
