The zookeepers are nursing to health a baby monkey which was rejected by its mother, until they determine she has the strength to be released back into the monkey enclosure.
... which would not happen in nature. I know it's hard to take, because it's so cute and so tiny and so ... so ... abandoned, but this monkey was supposed to die. It's a weird thing that humans do: they assume that they are above nature, and that what they believe is "good" is what is good, regardless of the nature of monkeys.
Estela is a pet now, and to pretend otherwise only speaks of humans' disconnect and poorly thought out good intentions.
I mean, the monkeys are already in cages at the zoo, which is a far cry from a natural habitat, but it annoys me to see photos of zookeepers "caring" for the animal when by caging them they aren't caring for them in the first place.