Science

Do Birds Grieve?

What seems like an obvious display of maternal mourning may really just be confusion.


It’s hard to imagine what a mourning bird would look like. But forced to guess, I would say the footage of two female Emperor Penguins huddled around a lifeless chick in BBC’s series “Penguins-Spy in the Huddle” comes uncomfortably close:

The accompanying narration supports this conclusion: “The mother invested everything in her chick.” the BBC reporter intones. “To lose it is a tragedy.” Even the clip’s producers call this “the most emotional clip we’ve ever filmed.” But does the bird actually feel the same great sadness that the image evokes in us? It’s hard to tell—even for scientists.

“I don’t think this is evidence of mourning,” says John Marzluff, a professor of avian social ecology and wildlife science at the University of Washington. “I see a response to a chick that is not responding, so the mother keeps trying the typical things,” such as sliding her chick toward the brood patch—the bare belly skin that transfers a mother’s body heat to her baby—and vocalizing to wake the unresponsive infant.

But Barbara J. King, an anthropologist at the College of William and Mary and author of the 2013 book How Animals Grieve, sees things differently—to her, the mother’s nudging of the tiny body with her bill, the vocalizing, and the camaraderie of her female companion all hint at something akin to grief. But to be scientifically sure, she argues, it would need to last longer. In clear cases of grief, she says, “we should observe prolonged signs of altered behavior in the survivor.” But for Marzluff, proving grief would need to be measured through the vista of a brain scan: If the mother’s hippocampus—the region in bird brains that is comparable to the emotional hub in mammal brains—lights up, “that might indicate grief,” Marzluff says. It’s this kind of deep evidence, he argues, “that we need to make a rock solid interpretation.”

Still, to support her point, King points to Kohl and Harper, two domestic mulard ducks that were brought to a New York-based rescue sanctuary in 2006. Both suffered an awful liver disease that resulted from their rougher days of force-feedings at a foie gras farm. Over the following four years, the ailing duo cultivated a very close relationship. “Ducks are social birds, but even so, the intensity of their bond was unusual,” King wrote in Scientific American in 2013.  Eventually, Kohl’s injuries got the best of him and he was euthanized. Harper was by his side. After Kohl passed, King writes, Harper kept pressing up against Kohl’s still body. Eventually he lay down and placed his own head and neck upon Kohl’s, resting in this somber position for some hours. Two months later, Harper passed away as well. When two animals share such closeness, King writes, “grief results from love lost.” Of course, King can’t determine the cause of poor Harper’s death. But it’s worth noting previous accounts of birds dying strangely after the loss of a close comrade: There was the duck that drowned itself after the death of its mate, as well as the young swan that committed the same act this year after discovering an older, lifeless swan—bystanders suspected it may have been the mother—floating in the lake.

Also difficult to ignore are what appear to be roadside funerals held by members of the corvid family. Sometimes, when one crow is struck and killed by a passing car, a fleet of fellow crows (in the realm of a hundred individuals in some cases) descend from the trees and walk circles around the deceased for 15 to 20 minutes.  The crow’s close black-and-white relative, the magpie, holds similar services—certain observations even reveal magpies placing clips of grass alongside the departed bird.

Another example—last month Explore.org’s Osprey nest-side camera recorded the loss of two month-old chicks. Moments after the nestlings were filched by a Bald Eagle, the parents were seen perched above their empty nest. The mother seemed to be surveying the land back-and-forth and emitting soft calls, perhaps in a cry out to her missing chicks.

So birds certainly possess the capacity to mourn—they have the same brain areas, hormones, and neurotransmitters as we do, “so they too can feel what we feel,” Marzluff says—but that doesn’t mean we know when it’s happening.

Though tender examples like the Ospreys and Kohl and Harper are quite moving, Audubon’s field editor, Kenn Kaufman, sees them as very soft proof of mourning in birds. He points to cases of flock birds, like Eskimo Curlews, which often lose group members to hunters. Sometimes, the whole flock will circle back to where their fellow bird has fallen. “It would be easy to interpret this as something like grief,” Kaufman says, “but it's more likely a result of confusion.”

Kaufman also recalls grisly experiments performed in the 1990s when scientists ousted one half of mated wild bird pairs just to witness the lonely result. The newly single bird often found a second mate quite readily, he says. In one Australian study, “I think the widowed bird had a new mate within half an hour.”

If birds do mourn, it seems some rebound more quickly than others.