It may be one of nature's more heartbreaking scenes: a mountain gorilla mother refusing to let go of her dead infant.
Last month in the Democratic Republic of the Congo's Virunga National Park, ranger Innocent Mburanumwe captured pictures of the first-time mother, Ruzuzi, appearing to grieve over her less-than-two-week-old baby. Ruzuzi kept the body with her for more than a week, according to Mburanumwe.
Gorillas have long been known to exhibit care for the dead. Mburanumwe, for instance, has seen behavior similar to that of Ruzuzi's on at least three occasions.
Virunga veterinarian Jan Ramer said, "While we can never know what is really going on in their heads, it sure seems some gorillas do mourn—or don't accept that the individual is dead.
"When an adult female died last year, her three sons stayed with her body for 24 hours," added Ramer, a regional vet manager for the Mountain Gorilla Veterinary Project who has studied mountain gorillas since the mid-1980s.
"I believe they were sad and confused, which is how I feel when I am mourning."
Photograph courtesy Virunga National Park
Surrounded by relatives in April, Ruzuzi (center) reclines with her baby's body by her side.
Ruzuzi belongs to the Kabirizi family, which is, at 38 individuals, the largest gorilla family in Virunga National Park. Like most Virunga gorillas, she was named after a park ranger slain in the line of duty.
The death of a baby may hit gorillas particularly hard, ranger Mburanumwe said. With a long gestation period and a high infant mortality rate, mountain gorillas successfully rear an infant only about every six to eight years.
In the case of Ruzuzi's baby, the cause of death is not known. But accidents to newborn gorillas are common, Mburanumwe said.
"When they're playing, they can kick each other," he said. And a first-time mother like Ruzuzi "doesn't always know how to protect the baby."
Young gorillas and adult females gather around Ruzuzi and her dead baby in an act of apparent sympathy or possibly even ceremony in April. Sometimes, the family members made soft, crying noises, ranger Mburanumwe said.
At times, he said, "it was like they were trying to see if the baby could get up."
Scientists generally resist the temptation to project human emotions on animals.
But watching the gorillas care for the dead baby, Mburanumwe said, he felt it was impossible to not draw similarities with people. "They were like human beings."