Do animals grieve?

 In 2018, an orca named Tahlequah gave birth to a daughter who tragically died within an hour. Despite this, Tahlequah refused to abandon her calf's body. For 17 days and over 1,600 kilometers, she carried it on her back, diving to retrieve it whenever it slipped away—even as it began to decay. Her altered feeding and travel habits were highly unusual, prompting the question: was she grieving or simply confused? Do non-human animals grieve?

This question has long been debated. In 1871, Charles Darwin suggested that animals experience a range of emotions, including grief. However, without a clear way to connect human minds to those of animals, many scientists have hesitated to attribute human-like emotions to them. Some believe that animals’ irregular behaviors after a death might serve adaptive purposes rather than signify grief. For years, humans were seen as unique in their capacity for complex emotions, while other animals were thought to act primarily on instinct. This view began to shift in the 20th century.

In 1985, for instance, Koko the gorilla—who had learned some American Sign Language—was told her kitten had died. She showed signs of distress and, weeks later, signed words like “cry,” “sad,” and “frown” while looking at a photo of another kitten. Since then, growing evidence has suggested that some animals, including mammals and birds, might experience grief.

In 2003, an elephant matriarch named Eleanor collapsed. Another matriarch, Grace, tried to help her stand and stayed by her side even after Eleanor died. Later, other elephants visited Eleanor’s body, with some rocking back and forth over it. Elephants have also been seen carrying the remains of deceased family members, such as tusks or jawbones. Similarly, in 2010, a giraffe calf with a deformed foot died after only four weeks. On the day of its death, 22 other giraffes gathered around its body. The mother stayed by her calf’s remains for days, refusing to eat, even after scavengers began consuming the corpse.

Scientists have also begun quantitatively studying animal responses to death. In 2006, researchers analyzed baboon fecal samples for glucocorticoids, stress hormones that increase in bereaved humans. Baboons who lost close relatives showed significantly higher glucocorticoid levels for a month after the death. They also increased grooming behaviors, broadening their social networks, which helped lower their stress hormone levels within two months.

Primate mothers have exhibited conflicting behaviors toward their deceased offspring, such as switching between carrying or grooming the body and cannibalizing or dragging it. These actions may reflect mixed impulses or emotional conflict.

Our understanding of animals’ emotional experiences, including grief, remains limited. To gain deeper insights into mourning in the animal kingdom, further research is essential. Meanwhile, this uncertainty raises important ethical questions. Do we assume animals are capable of grief and adjust our treatment of them accordingly? Or do we assume they are not, potentially causing harm? These decisions have significant implications, such as whether orcas should be kept in captivity or dairy cows separated from their calves. Until more is known, the question remains: which assumption is more humane?