In the July issue of Scientific American, anthropologist Barbara King of The College of William & Mary makes the case that animals ranging from ducks to dolphins may grieve when a relative or close companion dies. In so doing she departs from a long-standing tradition among animal behaviorists of assiduously avoiding projecting human emotions onto other animals. Not all animal responses to death qualify as mourning, however. King is careful to establish criteria for grief, noting that “researchers may strongly suspect grief only when certain conditions are met: First, two (or more) animals choose to spend time together beyond survival-oriented behaviors such as foraging or mating. Second, when one animal dies, the survivor alters his or her normal behavioral routine—perhaps reducing the amount of time devoted to eating or sleeping, adopting a body posture or facial expression indicative of depression or agitation, or generally failing to thrive.”

Here King describes two recent, well-publicized examples of animal reactions to death that illustrate the challenges of interpreting such behaviors:

“Occasionally the pull of anthropomorphism may overwhelm scientists’ normal caution in reporting animal responses to death. When Teresa Iglesias of the University of California at Davis and her colleagues published a paper in Animal Behaviour last year entitled ‘Western scrub jay funerals: cacophonous aggregations in response to dead conspecifics,’ the news media responded enthusiastically to the notion of a bird funeral. Yet nothing like a caretaking ritual around jay bodies actually had been observed. From a series of experiments, the scientists had discovered that scrub jays respond by vocalizing upon sighting the bodies of dead companions; they seem to be communicating information to their flock mates about potential risks in the environment. Iglesias told me last year, for my post about her paper at’s 13.7 blog, that ‘funeral’ is an apt term ‘only to the extent that it is an animal paying attention to another dead animal’ (and excluding behaviors such as scavenging). Any of the animal examples discussed in this article would, on this definition, quality as a ‘funeral,’ a too-generous application of the term.”

“In 2008 a chimpanzee named Dorothy died of congestive heart failure at the Sanaga-Yong Chimpanzee Rescue Center, a sanctuary in Cameroon. A popular chimpanzee with a warm personality despite enduring significant neglect and trauma at an amusement park in the years before her rescue, Dorothy had touched the lives of many apes at the sanctuary. A photograph of her ape companions watching as sanctuary staff carried Dorothy's body out for burial went viral globally, often under the headline of ‘A Chimpanzee Funeral.’ The image is moving, even arresting—because the watching chimpanzees are incredibly still and silent. Based on the photograph alone, though, we lack the information to invoke credibly a group-wide grief response; riveted and silent attention is not the same as mourning, and may occur also with intense curiosity. It's apparent from the rescue center's account that certain chimpanzees very close to Dorothy did show grief before the photograph was taken—right there at her body immediately after her death, expressed by touching Dorothy or screaming in distress. This example underscores the need for caution in describing animal grief, even in species where the capacity for grief is known.

Check out King’s feature article for some remarkable, well-documented cases of grief among our animal kin. Oh, and a word to the wise: get out the tissues.