Life as a carnivore is often tough. Prey must be captured, and depending on the predator, more than 80% of his attempts to grab prey can be unsuccessful.
For this reason, scientists have often assumed that predators take what they can get from their prey and can’t afford to be picky. . A killer whale kills more than 10 sharks in one day. Rather than eating up the flesh, the killer whale meticulously cuts off his liver and leaves the rest. Their killing corrupts. According to marine biologists, this particular organ preference is not strange for killer whales. They are known all over the world for chasing the best cuts from their prey.
“One of the best-known examples is in Eden, New South Wales, Australia, where whalers and killer whales worked together to hunt baleen whales,” says a PhD in marine biology from Flinders University in Australia. says Isabella Reeves, who is about to acquire the issue. These 19th-century whalers collected most of the carcasses, but killer whales ate the baleen whale’s tongue from the lower jaw. This is an unspoken agreement known as the “tongue law.” To this day, killer whales in various regions continue to eat whale tongues, she says.
In late February 2023, 20 dead sharks washed up on shore near the South African town of Gansbaai, with their bellies ripped open and their livers missing. The carnage was the work of just two killer whales, nicknamed Port and Starboard, who are known to hunt sharks in the area. His third killer whale has also been observed targeting shark livers in the area, suggesting Port and his Starboard may be teaching their neighbors their ways, he said. , said Alison Towner, a doctoral candidate at the University of Rhodes, South Africa. All over the world, killer whales tend to prefer shark liver, according to Lauren Meyer, a food chain ecologist at Flinders University. Carcasses of sharks whose livers have been removed by killer whales have been observed off Argentina, New Zealand and California dating back to at least the 1950s, Meyer says.
Killer whales have been observed tearing apart the livers of great white and seven-gill sharks near Gansbaai since at least 2015, said Ralph Watson, a marine biologist at South Africa’s Dyer Island Conservation Trust. The liver makes up about one-third of a shark’s body weight and is rich in a nutritious oil called squalene, making it very attractive to killer whales, says Watson. “Rough estimates suggest that one great white shark’s liver can keep him on one killer whale for a day,” he adds.
By comparison, the cartilage and muscle that make up most of the rest of a shark’s carcass may not be worth the effort, says Watson.
Orcas also seem to like penguin breasts and sunfish intestines, Meyer says. She, Towner, and Reeves are now doing research to understand what nutrients killer whales gather from these parts of their prey. part is wonderfully soft. “As long-lived animals with one set of teeth, minimizing dental wear, if possible, supporting soft-tissue selection, may be key to living a long and healthy life. ‘ she says.
And it turns out that killer whales, members of the dolphin family, are not the only predators with a preference for certain organs. There is growing evidence, both on land and in the sea, that other carnivores may seek out specific prey to maximize energy intake and/or nutrition.
“There are times when food is plentiful, and there are times when prey is scarce, but there are other pressing situations that may feed first in certain ways,” says Kevin Cole, an animal physiologist and microbial ecologist at the University of Pittsburgh. We have priorities,” he said. “We have overlooked many nuances about carnivore biology.”
A 2013 study in the journal found that great white sharks that scavenge for whale carcasses first choose fatty spots, sometimes even spitting out chunks of meat and reverting to more fatty bites. pro swanCape fur seals enjoy feeding on the energy-rich liver of blue sharks. A 2010 study found that Alaskan spotted seals eat all but the head of a male salmon they catch, but only the egg-rich belly of female salmon.
Christopher Dickman, a terrestrial ecologist at the University of Sydney, says eggs are often an attractive diet for predators. The female spiny devil, a spiky lizard endemic to Australia, is a favorite target of peregrine falcons during mating season because the lizard holds dozens of eggs in its belly. In a falcon’s nest, “there are two to three dozen spiny demon corpses of him, with ripped bellies and missing eggs,” says Dickmann. “Eggs are an excellent source of nutrition for almost anything you want.”
Terrestrial predators may also exhibit a preference for certain body parts. For example, wolves chase the guts of deer and other large prey. Brown and black bears focus on the oily brains and nutritious eggs of salmon when fish are abundant, and only design to eat whole fish in years when salmon are not abundant.
Dickmann found less dunnart on hairy legs (Sminthopsis Youngsony) and Wongai Ningawi (Ningau laughed) — small mouse-like marsupials of the Australian desert — feed preferentially on the abdomen and thorax of insect, spider, and centipede prey. “They don’t really like legs,” Dickmann explains.
He and his colleagues also found that these marsupials deliberately hunt down wolf spiders, despite research showing that they are no more nutritious than other arthropod prey. In this case, the wolf spider eats other insects that the dannat likes to eat, so hunting the wolf spider not only provides a delicious meal, but also removes a source of competition for other foods.
But it’s still unclear to what extent wild animals are aware of their nutritional needs and can make intentional choices based on their needs for specific vitamins and minerals, not just for energy, Cole said. After eating a few servings of starchy food, humans may crave a green salad. Herbivores are also known to look for specific nutrients in the plants they eat, he said. Say. Do carnivores experience similar cravings? Hard to say.
“I think we have very little understanding of what animals go through in their day-to-day lives,” Cole says.
