Whales are known for their intelligence—and now they may become known for their emotions and parental instincts, too. A study in the Journal of Mammalogy has found that at least seven species of toothed whales—including killer, sperm, and short-finned pilot whales, as well as four dolphin varieties—have been found swimming close by and touching and pushing the bodies of dead younger whales, offering evidence that they mourn their young when they die, National Geographic reports.
"They are in pain and stressed," says study co-author Melissa Reggente. "They know something is wrong." The findings add these marine mammals to other animal species—including elephants, giraffes, and chimps—that have been witnessed exhibiting grieving-type behavior.
The scientists involved with this study examined (mostly unpublished) reports pertaining to these seven species and their apparent mourning habits in three different oceans, observed by other researchers on the open water.
One scientific expedition in the Red Sea, for example, witnessed an Indo-Pacific bottlenose dolphin push the corpse of a smaller dolphin through the water; another case showed a female killer whale carrying a deceased newborn whale in her mouth.
The researchers noted these cases involved an adult grieving for a calf or juvenile whale and that they were probably related. While it may be tempting to say the whales were just acting out of curiosity or couldn't turn off their nurturing instincts, National Geographic points out that following a dead whale like this can put the living whale in peril because it's not eating or maintaining social relationships with other whales.
Instead, researchers say, the study lends credence to the fact that "adults mourning their dead young is a common and globally widespread behavior in long-lived and highly sociable/cohesive species of mammals." (Sperm whales can also use their heads as battering rams.)
This article originally appeared on Newser: Whales Grieve for Their Young Like Human Parents