A macaque was seen holding on to a dead baby macaque in MacRitchie Reservoir on Saturday, June 12.
The heartbreaking sight was captured by a photographer, Dennis Chan, and uploaded to Facebook.
The adult macaque, believed to be the mother, was seen holding the lifeless baby in its arms.
Photographer shooting photos of wildlife
Chan stopped in his tracks to observe the scene.
According to him, it was 11am when he witnessed the incident at the reservoir while taking photos of wildlife and birds.
According to him, the adult macaque swatted flies away from the dead macaque's body, which appeared to be an infant macaque.
Chan said: "The female long-tailed macaque was still holding on the lifeless body of the baby and I believe that she still thinks that the baby is alive. She even made attempts to get rid of the flies that started swarming the poor baby."
Chan said he observed the pair for about half an hour.
The adult macaque was seen lifting the baby macaque and and putting it back down again.
The photographer left shortly after.
Monkeys responding to death
Long-tailed macaques are highly intelligent and adaptable, and have come to be seen as a nuisance to the public in Singapore.
Members of the public are advised to take conscious steps to avoid human-animal conflict as macaques are still wild animals.
One way to do so is to not feed these creatures.
And as highly sociable animals, monkeys are known to respond individually or as a group to a death in the group.
Adult monkeys have been seen carrying their young around as if overcome by grief.
A large monkey troop was witnessed mourning the death of a young one as a group.
All photos via Dennis Chan