Much has also been written about how elephants stand vigil by their dead peers. Elephants also appear to be especially reverential toward elephant bones they may find in their travels. Ian Douglas-Hamilton, author of “Among the Elephants,” has described how one elephant tried to push up a dead herdmate with her tusks, and later made repeated visits to the remains.
Chimps, bonobos (pygmy chimpanzees) and other ape mothers have been known to carry around dead infants in a symbolic denial of death. Likewise, dolphins may continue pushing their dead offspring to the surface for a considerable time after death.
Bonobos have also been observed throwing rocks at dead troopmates and beating their chests in what can look like primitive CPR. Primatologist Frans De Waal from Emory University believes that bonobos have some conception of the permanency of death.
When one bonobo kills a deadly viper, the rest of the troop seems to understand that the snake is permanently dead and instead of avoiding it, they will then approach it, and even examine its fangs and wear it around their necks.
In Botswana, University of Pennsylvania zoologist Anne Engh measured biochemical markers in fecal samples of baboons, who witnessed a predator kill a troopmate. These readings, which reflect stress, were higher than average for the baboons who saw the event, but even higher for family members of the victim, suggesting some conception of personal loss.
Skeptics may still question where these behaviors really indicate mourning or if they are fully explained by instinct, evolution or conditioning. Are cats seeking out lost companions, or simply marking their newly expanded territories? Are those depressed and devoted dogs expressing love for departed owners or merely adhering to daily routines created by past conditioning?
In addition to bereavement, altruism is another social behavior, often attributed only to humans, that has been studied extensively in animals. Selfless concern for the well-being of others is something we typically don’t associate with the unforgiving world of nature. Nevertheless, field studies have reported food sharing among animals as diverse as wolves, chimps, ravens and even vampire bats and vicious housecats. The adoption of abandoned orphans has also been frequently observed in the wild.