The cause of the young macaque's death, which happened on January 18, is unknown since zookeepers have been unable to get the baby away from the mother. The mother acts aggressively even to other macaques who approach her.
This story resembles another tragic story of the mother gorilla who grieved the death of one of her twin children.
"The mother-infant bond in primate species is quite strong, and it is not uncommon for a mother to carry a deceased infant for hours or even days," Steve Ross, director of the Lester Fisher Center for the Study & Conservation of Apes at the Lincoln Park Zoo, told The Dodo at the time.
We can only hope the mother will recover, with time, from this loss.