Growing Up Slowly
"Misha's got a rat!" I yell to Tim in my astonishment. The young ape bites off the rat's head and swings it by the tail like a stuffed toy.
Orangutans rarely eat meat, and in this case Misha seems motivated more by curiosity than by appetite. She also occupies herself with the orangutan version of playing house, making a simple nest and practicing the skills of independent living she'll need when Marissa, her mother, one day turns her attention to a newborn.
The pioneering work of Biruté Galdikas suggests that orangutans bear offspring only once every eight years on average—an extremely long interval among mammals.
After a mother gives birth, her baby will cling to her for several years, rarely venturing away from her side, and continue to nurse for about six years. A juvenile sibling may stay with its mother for a few years, as does Emy with mother Ely and her infant.
Emy is learning how to fend for herself since, unlike human mothers, orangutans normally do not provide food for their offspring beyond lactation.
One of my research goals is to try to determine why these periods of juvenile dependency last so long.