National Geographic: At the Sanaga-Yong Chimpanzee Rescue Center, more than a dozen residents form a gallery of grief, looking on as Dorothy—a beloved female felled in her late 40s by heart failure—is borne to her burial.

Prior to being brought into the center, Dorothy was trained to drink beer and smoke cigarettes at an amusement park in Cameroon. About Dorothy’s death and burial, a volunteer at the center said:

The management at Sanaga-Yong opted to let Dorothy’s chimpanzee family witness her burial, so that perhaps they would understand, in their own capacity, that Dorothy would not return. Some chimps displayed aggression while others barked in frustration, but perhaps the most stunning reaction was a recurring, almost tangible silence. If one knows chimpanzees, then one knows that [they] are not [usually] silent creatures.