Scientists working in Mexico have recorded a number of incidents in which a gaggle of orcas hunt younger great white sharks and eat their energy-rich livers.
While orca pods in South Africa, Australia and California have been recorded participating in related conduct, that is the primary time that it has been documented in Mexico, in accordance to a examine revealed in the journal Frontiers in Marine Science on Monday.
In one incident, recorded in August 2020 utilizing numerous cameras in addition to a drone that captured aerial footage, a gaggle of 5 feminine killer whales have been recorded working collectively to assault a younger white shark and take away its liver, earlier than sharing it between them.
A couple of minutes later, the group assaults one other younger white shark, efficiently eradicating the liver.
Another recording dates to August 2022, when a combined group of orcas have been recorded attacking a younger white shark in the identical location, then consuming the liver.
The examine famous that in two of the three recorded predation occasions the orcas immobilized the shark by flipping it onto its again and deftly averted bites that would thwart the assault.
By turning the shark over they could induce “tonic immobility,” which makes the shark simpler to manipulate, it added.
“Prey handling and inducing tonic immobility may be more easily achieved in smaller white sharks compared with larger individuals, thereby also reducing risk of bite injury,” the examine stated.
“Our evidence undoubtedly shows consistency in the repeated assaults and strikes, indicating efficient maneuvering ability by the killer whales in attempting to turn the shark upside down, likely to induce tonic immobility and allow uninterrupted access to the organs for consumption,” it added.
Study writer Erick Higuera, a wildlife cinematographer and marine biologist at Conexiones Terramar, a nonprofit group, advised NCS that he was shocked that the orcas hunted white sharks in the identical space in completely different years.
This might counsel that juvenile white sharks have gotten a daily seasonal prey goal for orcas, which might “represent a significant additional pressure” on white shark populations, in accordance to the paper.
“This provides more information on the ecology of orcas in the Gulf of California, which can be used for the conservation and preservation of both white sharks and orcas,” stated Higuera.
Alison Towner, a marine biologist from Rhodes University, South Africa, who was not concerned in the examine, advised NCS that the proof introduced by the examine was “strong.”
“Drone footage is invaluable here – we first captured and published drone footage of orcas killing white sharks in South Africa, and it changed what we understood about these interactions,” she stated.
“This new footage from Mexico lets us compare behaviour across different orca groups and shark populations.”
Towner highlighted that, whereas the conduct has been proven not to be an remoted prevalence, it isn’t widespread throughout all orca populations.
“It appears to be specific to certain orca groups that have learned this technique, and the impact depends on how frequently the behaviour occurs in a given region,” she stated.
“Once the technique exists in a group, it becomes part of their hunting culture,” stated Towner, who underlined the concentrating on of the shark livers, that are wealthy in vitamins and enormous relative to the animal’s dimension.
“For orcas that know how to safely handle a shark, the nutritional reward is very high.”