Animal care staff at the San Diego Zoo are getting some unique helpers as they assist an endangered 7-week-old François’ Langur Monkey: The entire Langur troop pitches in to socialize the baby, while keepers make sure he gets enough food and care.
After the baby, named Chi, was born in February to mother Mei Li, keepers noticed that she rejected her baby and failed to nurse him. The staff hoped that other members of this troop might decide to raise the baby, because Langurs practice alloparetning, where all members of the group participate in rearing young – but the other Langurs also rejected the infant.
“Infants need to nurse every few hours in order to stay healthy,” said Mindy Settles, primate keeper at the San Diego Zoo, adding that keepers intervened right away to feed the baby before his condition deteriorated. “Every day, we did introductions trying to pair him back with mom; and it wasn’t actually until he was over a week old—almost a week and a half old—that mom picked him up and actually held him for the first time.”
Rather than remove Chi from the troop and hand-rear the baby in the nursery away from his family, keepers decided to use assisted-rearing techniques. Because the animal care staff has established a bond of trust with the Langurs, the troop allows keepers to remove Chi for feedings, then accepts him when he returns to the troop. This allows Chi to develop normal social behaviors and understand that he is a Monkey, not a human, and hopefully breed one day with a female.
“I can’t stress enough how amazing this opportunity is for us,” said Jill Andrews, animal care manager for primates at the San Diego Zoo. “The amount of cooperation between the Monkeys and the keepers for the care of this 7-week-old infant is, frankly, astonishing. He is way ahead of the curve.”
Francois’ langurs are a species of Old World Monkey native to Asia—ranging from southwestern China to northeastern Vietnam. The species is listed as Endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, due to a 50 percent decline in their population over the past 30 years. Hunting to supply body parts for traditional folk medicines is a primary reason for their diminished numbers. Habitat loss and fragmentation due to agricultural development has also had a negative effect on the population.