United in what appears to be deep and profound grief, a phalanx of more than a dozen chimpanzees stood in silence watching from behind the wire of their enclosure as the body of one of their own was wheeled past.
This extraordinary scene took place recently at the Sanaga-Yong Chimpanzee Rescue Center in Cameroon, West Africa.
When a chimp called Dorothy, who was in her late 40s, died of heart failure, her fellow apes seemed to be stricken by sorrow.
As they wrapped their arms around each other in a gesture of solidarity, Dorothy's female keeper gently settled her into the wheelbarrow which carried her to her final resting place - not before giving this much-loved inhabitant of the centre a final affectionate stroke on the forehead.
Enlarge Chimpanzees appear to console one another as Dorothy is carried to her final resting place in a wheelbarrow
Locals from the village serve as 'care-givers' to the chimps - something hugely needed by the animals who are all orphans as their mothers were killed for the illegal bushmeat trade.
Hunters captured them as young babies, often still clinging to their mother's bodies, to sell as pets.
Until recently, describing scenes like this in terms of human emotions such as 'grief' would have been dismissed by scientists as naive anthropomorphising.
Enlarge On sale now: National Geographic
But a growing body of evidence suggests that 'higher' emotions - such as grieving for a loved one after death, and even a deep understanding of what death is - may not just be the preserve of our species.
Chimpanzees - as you can see in the November issue of National Geographic magazine, on sale now - and the closely related Bonobos maintain hugely complex social networks, largely held together by sex and grooming.
They have often been observed apparently grieving for lost family and tribe members by entering a period of quiet mourning after a death, showing subdued emotions and behaviour.
And such complex emotions are not the preserve of primates or even mammals. Just this month, for instance, Dr Marc Bekoff, an ethologist at the University of Colorado, reported evidence that magpies not only appear to grieve for their dead but carry out something akin to a funeral ritual.
In one instance, a group of four magpies took it in turns to approach the corpse of their dead comrade.
Two of the birds then flew off to return with a piece of grass, which they laid down by the corpse. The birds then stood vigil.
In fact, there is a large body of anecdotal evidence that corvids - the group of super-bright birds that include crows, magpies and rooks - engage in many sophisticated social rituals.
But the most famous nonhuman death rituals are those of elephants, who will often spend days guarding a dead body, gently prodding the remains with their trunks and giving the impression of being lost in grief.
Elephants are highly social, long-lived and intelligent animals, whose excellent memory is no myth.
It is perhaps unsurprising that the loss of a member of the clan produces an emotional reaction.
The evolution of human death rituals is lost in the mists of time. There is some evidence that now-extinct hominid species such as the Neanderthals appreciated the significance of mortality, burying their dead and even scattering the graves with flowers.
Seeing a group of chimpanzees, our closest relatives, apparently paying a sad and heart-rending tribute to their much-loved lost sister gives us, perhaps, a window on how this deepest and most fundamental emotion evolved in our own ancestors.
Read more: http://www.dailymail.co.uk/sciencetech/article-1223227/Is-haunting-picture-proof-chimps-really-DO-grieve.html#ixzz0VJhgjCRP