Speaking the right language

Size: Head and body: Up to 22"/56cm

Tail: Can be body length again

Weight: 3-11 lbs/1.3-4.8 kg

Average life span in the wild: 20-25 years (up to 40 in captivity)

Diet: Omnivorous (fruit, nuts, seeds, insects, bird eggs, small birds)

Capuchins live in highly social groups of between six and forty members. In the wild they spend the day mainly in trees.

They have a long infancy with childcare shared within the group (males too). Then there's an extended pre-adult period: like us, they have a lot to learn. For survival they need to understand complex group dynamics and hierarchies. Important methods of communication they pick up at this time include body language, facial expression, social grooming and interactive play and vocalisation.

There are various subspecies within the category, with no final agreement on classification. Learning the right language seems to be crucial: when the monkey that inspired my story, a weeper capuchin, was rescued from the pet trade and placed in a sanctuary, he met another resident, a black capped capuchin, who greeted him with an excited high-pitched black cap greeting. This unfortunately was similar to an aggressive high-pitched weeper attack noise, and was interpreted as such. After that, the two never quite hit it off.

Pepito in my story is forced to live on the ground, alone, chained up. The tragedy of wanting to return him to the wild is that he has no social experience - doesn't know how to forage for his own food, won't understand the dangers from others of his kind as well as predators and doesn't know how to communicate.

More about these clever creatures tomorrow.