In 2018 a whale behavior wasfilmed for the first timeoff easterly Canada . rather of hurl after Pisces the Fishes , the humpback whales stayed nearly motionless while opening their mouths wide and letting the fish come to them . Interest from marine biologists bend to amazement when the same behavior was described amongBryde ’s whalesin the Gulf of Thailand , quickly going viral . Other accounts have since poured in , raising the query of whether we had somehow missed this proficiency all along , or if something had change , and if so what .
formally this approach , named trap or pace - water eating , had never been account before 2014 , despite jillion of time of day expend watching the two specie . However , Dr John McCarthyof Flinders University conceive that might be wrong . He has obtain elaborated descriptions of what seems to be the same natural action in the most unlikely of places : a 13th - one C Norse manuscript . Shorter accounts that also come along to relate to the same thing date back almost two millennium .
In a fresh newspaper , McCarthy and colleague present the line of reasoning that gob - alimentation was actually once common enough that observant sailors reported it several time in the past .
Diagram of humpbacks engaged in trap feeding; with a jaw either flush with the waterline, or raised to a similar height to the rostrum (J. McCarthy)
“ I saw the video footage , ” McCarthy order IFLScience . Subsequently , he interpret a verbal description of whale conduct in chivalric Norse writing and “ find out a parallel " . Norse tale of the sea refer to a creature name a hafgufa – often fuddle with theKraken(which is Norse , not Greek ) – which is considered a mythological brute . However , while researching McCarthy noted that in works such asThe King ’s Mirror , the hafgufa is explicitly referred to as a type of giant that feeds by hold back for Pisces to swim into its mouth .
TheKing ’s Mirror ’s description of the hafgufa is clear magnified and the source proposes there are only two of them in the entire sea . However , the other expression could be a modern description of trap feeding . The King ’s Mirrorhas been found to contain a unco accurate account of at least 26 other animal species , so there is reason to take it gravely .
On reckon deep McCarthy discovered the more fantastical hafgufa reference are ulterior additions , from the 18thcentury . Those , likeThe King ’s Mirrorthat date from Medieval times , consistently fit well with the behavior get word in recent eld .
An illustration of the hafgufa from the Icelandic Physiologus (c.1200) depiction of the Apsido feeding (Reykjavík AM 673 a II 4to fol. 3v Public Domain, color and contrast corrected).
Moreover , the Norse were not the first to report the phenomenon . A Greek textual matter attributed toPhysiologusand thought to have been write in Alexandria around 150 - 200 CE also check a extension . The original has been lost , but a Latin transformation kick in a alike description , albeit less specific than the one inThe King ’s Mirror .
An ancient feeding practice hold more sense than two species of hulk severally discovering a new attack in upstage ocean . However , it bring up the interrogative why either whale coinage stop feed this fashion for hundred , or nobody discover despite frequent human - heavyweight fundamental interaction in the 20thcentury .
Both humpbacks and Bryde ’s ( label brood - es ) whales arerorquals , baleen hulk that hunt mostly by lunge - feeding . The paper proposes rorqual course this way only when fish are relatively scarce . Presumably , it drive a pot less energy to float at the surface and open one ’s mouth than to actively chase food . That makes it a worthwhile strategy when restoration are expected to be poor .
A map of Iceland from 1658, surrounded by mythical creatures - except that one of them might not be so mythical: the hafgufa, enlarged below. Public domain
In the 19th and 20th one C , industrial - scale whaling beat back razorback almost to experimental extinction . Stocks of their preferred prey were often overharvested as well , but not as drastically . Consequently , the authors suggest , the few heavyweight that exist probably had plenty of food to choose from . They could concentre on gamey - try / high - reward approach such as straight thrust andbubble - meshing feeding .
If this is on-key , the return of trap - feeding could be an indicant of the recuperation in rorqual number , something that is certainly think to be take aim place with hunchback . late report ofhumpbacks singing lessand arecord - break podof fin whale are thought to be signs the recovery among big whales is changing their behaviour , so it ’s plausible previous hunting techniques are being recover .
A ordered feature film of the ancient account of trap feeding is that the whale used smells to lure Pisces the Fishes into their oral fissure . This has not been observed , but the whale sometimes cough up filtered prey beforehand , perhaps as a hook , and the odor is emphatically strong .
McCarthy told IFLScience the paper ’s finis could be tested by “ valuate the density and distribution of prey , ” where trap feeding is observed , along with investigation of pee conditions . Observers may also await out for similar behavior among other species of rorqual . “ Hopefully if nothing else [ the newspaper ] will pep up more research , ” McCarthy sound out .
The newspaper is published inMarine Mammal Science .
