athirst elephant seals go out on the prowl in search of lantern Pisces and squid to fill their empty belly after weeks marooned on beach nursing their pups , but until recently it was n’t known how the Orion knew where to discover their quarry in the inky sea depths . fresh research published in theJournal of Experimental Biologyset out to answer what gave the fair game ’s berth away by flog camera to the seals ’ head to get a sealing wax - eye - view of the quest , and the footage is dazzling .
" Bioluminescent organisms are the master source of brightness level ( 80 percent ) in waters deep than 500 metre , " say Pauline Goulet from the University of St Andrews , UK in astatement . Lantern Pisces and calamary can make two kinds of light , a continual dim gleaming to act as countershading and vivacious flash to confuse attackers . The research worker on the study wondered if these bright flashes essentially gave the position of the prey animals away to hungry seals , or if the burnished lights actually acted as an effective pickup against elephant stamp .
To find out , Goulet and colleagues decided to capture the cat - and - black eye chase between the stamp and their prey to see how the fight played out underwater . for paint a elaborate picture of the events , they take a tag that could lumber the seal ’ movements as well as recording the flashes of twinkle from the bioluminescent snacks . " Because the bioluminescent flashes are so light , typically less than a second , the tags need a very fast light sensor , ” Goulet explicate .
They charter the kit to the Kerguelen Islands , also known as the Desolation Islands , in the Antarctic and attached it to five elephant seal mothers , making sure to keep an middle out for approaching seal who can be a bit nippy . Two month later , of the five seals , they were able-bodied to call back tag from four of them and the information analyses expose that most of the hungry mums had popped off on a 3,000 - klick ( 1,864 - naut mi ) journeying in lookup of nutrient , with depth ranging from 79 to 719 meter ( 260 - 2,360 foundation ) .
After fastidiously analyzing more than 2,000 bioluminescent jiffy , the investigator recognize that the quarry brute were flashing to spook their assailant . " The prey always emits a flashbulb the second the seal launches an attack , which suggest that the flash is a defensive reaction when the prey realizes it is being attacked , " said Goulet .
A flashing squid being pursued by a diving elephant sealing wax . credit entry : Akinori Takahashi , The Graduate University for Advanced Studies . Reproduced with permit of The Company of Biologists . Yoshino , K. et al . ( 2020 ) . Acceleration - triggered brute - borne TV show a dominance of Pisces in the diet of distaff northern elephant seals . J. Exp . Biol .
The SEAL were more successful in eating prey that did n’t flash and had a harder time catching those that did . Amazingly , one seal appear to do a false lunge by twitching their head so that the fauna would flash and give itself away . The flash is therefore adaptive in helping the prey to escape but can also be exploited by savvy seals who have time on to the performance . Goulet and Johnson next desire to be able to identify on the nose which animals the seals are nosh on by decrypt their typical flashes .
