麻豆淫院

Like a proud cat leaving a bird on its owner's doorstep, orcas鈥攁lso called killer whales鈥攎ay sometimes offer to share their prey with humans, according to research in the Journal of Comparative Psychology.

In the study, researchers from Canada, New Zealand and Mexico reported on 34 interactions spanning two decades in which orcas in the wild attempted to offer food to humans. The incidents took place in oceans around the world, from California to New Zealand to Norway to Patagonia.

"Orcas often share food with each other鈥攊t's a prosocial activity and a way that they build relationships with each other," said study lead author Jared Towers, of Bay Cetology in British Columbia, Canada. "That they also share with humans may show their interest in relating to us as well."

Towers and his colleagues, Ingrid Visser, Ph.D., of the Orca Research Trust in New Zealand, and Vanessa Prigollini, of the Marine Education Association in La Paz, Mexico, collected and analyzed information about 34 incidents of food sharing that they and others had experienced. On 11 of the occasions, people were in the water when the orcas approached them. In 21 cases, they were on boats, and in two cases they were on the shore. Some were captured on video and in photos; others were described in interviews with the researchers.

In order to be included in the analysis, the incidents had to meet strict criteria鈥攊n each case the whales had to have approached the people on their own (the people could not have closely approached the whales) and dropped the item in front of them. In all but one of the cases, the orcas waited to see what would happen after they made the offering, and in seven cases they tried more than once to offer the food, after the people initially refused it.

Domesticated animals like dogs and cats sometimes offer food to humans, but this research marks some of the first detailed descriptions of similar behavior in non-domesticated animals. It makes sense, according to the researchers, because orcas are intelligent and social animals that use food sharing as a way to build relationships with kin and unrelated individuals. They also often hunt prey much larger than themselves, and thus sometimes have food to spare.

"Offering items to humans could simultaneously include opportunities for killer whales to practice learned cultural behavior, explore or play and in so doing learn about, manipulate or develop relationships with us," the researchers wrote. "Given the advanced cognitive abilities and social, cooperative nature of this species, we assume that any or all these explanations for, and outcomes of such behavior are possible."