No one knows precisely what happened that afternoon, but it must have gone something like this: Dianne had been tending her baby, as would any mother with an infant born just three days earlier. At times she cradled him in her massive, hairy arms and gazed at his wrinkled face. Sometimes she sat and held her baby close to her chest. When she moved about, she took him in the crook of her arm and walked carefully, supporting herself on one arm and two legs. It had been an intense three days in the life of a mother who had lost another infant to stillbirth, and except for the fact that she was separated from her friends and relatives, it had been a good time.
Now, however, it was the afternoon of the Fourth of July. The humans had started arriving early in the hills of Griffith Park, and the various yelps, laughs and shrieks of picnicking families were punctuated with the sporadic patter of firecrackers. Then, probably sparked by stray fireworks, the grass ignited and flames raced over the hillside. Smoke billowed into the sky and settled over the compound where Dianne was kept separated from the other gorillas. There is nothing so disturbing to any animal as smoke, and it must have been terrifying to the gorilla, a species that has very few offspring and compensates by forming a strong bond with them and investing years of care. But worst of all, she was isolated. She could hear the other gorillas; they were just beyond the wall. But she could not touch them--could not draw comfort from a glance or a grunt from Chris, the big, protective male. Almost certainly, the hidden programs of survival came on line, and Dianne must have stridden back and forth along the walls, scanning the top for some handhold, some way to climb out and save her infant. But there was no way out.
Suddenly, a gigantic shape appeared overhead, blotting out the sky with its enormous wings, emitting a deafening roar. At tree level it flew, looming over her, a split-second later disappearing--a borate bomber flying in to douse the fire.
There is no doubt that Dianne panicked. In her arms was her infant, her genes, packaged in this tiny piece of life for the next generation. In her massive body was her own life. The next morning the infant was found dead--of concussion, the autopsy concluded. The ape had probably lunged for cover, holding her baby in one arm, and accidentally smashed it against a rock.
Much was learned about the maternal instinct of gorillas in those few days, however. Before this episode, it was thought that captive gorillas were not fit to be mothers; early attempts at the Los Angeles Zoo to allow the offspring to remain with the parent had resulted in several cases of abandonment and fatal beatings. One mother ate her infants as soon as they were born. The young mothers were not able to express their nurturing instincts, so the thinking went, and frustration had no outlet but rage.
Breeding in captivity is a relatively recent program in the history of zoo gorillas. As recently as 20 years ago, the animals were wrenched from the wild, the mothers killed and the young taken. At the time, zoo officials assumed that the survivors, being raised by human keepers, had not learned the complex skills of handling and nurturing a simian infant. And because gorillas have always been so valuable--the going price now is about $75,000--zoos would isolate the females as soon as they became pregnant in order to ensure a bland, safe pregnancy. After the delivery, the keepers would snatch the infants away to the zoo nursery. Females were sometimes anesthetized on entering labor so that the infants could be removed quickly. In the case of the cannibal mum, births were by Caesarean section.
Today, the Los Angeles Zoo is about to challenge the idea that a zoo-born gorilla is incapable of quality mothering, partly because Dianne, until the time of her loss, was performing remarkably well. Although she was born in the wild, she was taken into captivity at about 1 year of age.
The implied conclusion is that mothering may be far more innate than learned--that the basic desires and skills may be pretty much a complete behavioral structure, something like a completed house that needs only the finishing touches--paint and furnishings--in order to be lived in.
From studies in the wild, we now know that social interaction is the center of gorilla life; just being among others is security and comfort in times of stress. Therefore, isolating pregnant females amounts to solitary confinement. It seems to have been the loneliness and frustration resulting from the social deprivation that perverted the maternal instinct.