David was about five feet ten; with a sturdy build long black hair parted down the middle and round wire rimmed glasses. He continued to monitor what was left of Group 4, but had taken advantage of Amy’s absence that day to take some comparative notes on group 5.Once inside our cabin, he tried to maintain his usual dry demeanor, but a smile quickly took over his entire face.”Puck had a baby” No response, “I didn’t see it happen, but I think she must have had it while I was there because she was still licking off birth fluid”.

She baby. The words finally kicked in and we sat there stunned. It was greasy news, unbelievable news. But it would be dishonest to say that Amy didn’t feel some disappointment, too. Day after day, month after month she stayed with the group, rarely missing a day in the field. Yet first she had missed Liza’s transfer and now a birth! Gorilla females give birth only every four years, so it is a rare event. No one had ever witnessed a birth in the wild, although Kelly Stewart believed that one occurred while she was with Group 4.Does the mother go off alone? Or do others help? Does she squat or lie down? What does she do with the umbilical cord? Does she vocalize in any way? How amazing it would be to watch a new gorilla enter the world. The thoughts came in rapid succession, until the most fundamental question took over; how did puck have a baby?

Gorilla males have disproportionately small genitalia for their size. At the same time, mountain gorillas are very well endowed with long body hair that covers all but parts of their hands, feet, chest and faces. So, while it’s easy to see the penis and scrotum on very young gorillas, they virtually disappear from sight after the age of two. Somehow, Puck’s lack of a penis had eluded detection by Dian in “his” early years and her true gender has subsequently gone unnoticed by Sandy and others. We wondered if there were other such cases.

Over the next few weeks, Amy and David took advantage of their accepotance by the gorillas to investigate who had what below the bulge of their bellies. With Puck now out of the closet, only three other older sub adults needed to be checked. Rest periods provided the best opportunity the next week when he came to inspect Amy‘s red bandanna. While the five year old sat to examine the bandanna, Amy methodically parted the hairs between Tuck’s leg. There, a small black protuberance was clearly visible, but it didn’t match the expected size or shape. After further examination, she determined that Tuck in fact had a sizable clitoris. Tuck seemed unbothered by the inspection, but Amy came back to the cabin in disbelief. Puck and Tuck were sisters! A few weeks later, David would report that four-year –old Augustus from Group 4 should hence forth be known as Augusta.

Three of the four older sub adults in the two mains study groups had been incorrectly sexed. Amy sent a quick note to Sandy Harcourt and Kelly Stewart at Cambridge to let them know that they might want to review any gender analyses in their nearly completed doctoral theses. Amy’s own work would need some modification, too, since Puck’s feeding patterns would now be analyzed as those of a pregnant female, not a growing young male. Puck would also be added to the list of females, not transfer out of their birth families, but instead stayed to breed with either her father, Beethoven, or half-brother, Icarus. The good news, from a conservation perspective, was that the Virunga gorilla population now had three more females who would likely produce a total of ten to fifteen surviving off springs for the next generations.

IN THE DAYS AFTER the great Virunga Sex Change, it was interesting to consider how presumed gender differences might have influenced our own perception of individual’s behavior. Puck and Tuck were both very active and confident gorillas. Both liked to play and seemed to have equal, if not superior, standing in comparison with the other young males in their group. We had actually discussed whether Puck or Ziz was more likely some day to emerge as the dominant silverback in group 5 if Icarus remained on the periphery or went off as solitary male. Tuck was the most curious of all the gorillas, always approaching to inspect new patches on our clothes or boots, examine freckles, or tug on bootlaces. Puck once took Bills binoculars and lifted them to look through the larger end. As she moved her hand slowly back and forth beneath the binoculars, Bill wondered what she thought of the “little” fingers she saw through the smaller lenses. Exceptional as much of this behavior might be for gorillas, it seemed to us to be stereotypically “male” outgoing assertive, exploring. Now we could shed our preconceptions and see that it was normal female gorilla behavior too.

For an alternative explanation of Pucks and Tucks standing in Group 5, one had to look no further than their mother. Effie was the highest ranking of the clan’s females. In conflicts over food, Effie’s posture, cough grunts and apparent willingness to fight if necessary almost always carried the day. She was one of the first to enter the clay cave and had at least three off springs in the group, four, if the young silverback, Icarus was hers too. Even Beethoven yielded to Effie at times when she decided to follow a different trail or seek a better nest site.

One day, a powerful storm swept down from the saddle and caught us all off guard. At the first clap of thunder, the females bolted for a nearby fallen Hagenia. Effie arrived first, followed by Pantsy, Amy, and Tuck. Bill arrived a few seconds later and found only enough space to cuddle up next to Tuck, leaving his lower body out in the soaking rain. At first, Beethoven sat stoically in the gorillas classic rainy weather position arms folded, head tipped down, with water running off his long hairs. This “wet Buddha” position was usually an effective strategy for at least an hour. After five minutes of exceptionally heavy down power, though, Beethoven rose up and strode over to where the five of us crowded into our crude Hagenia shelter. He stood in full strut with his chin out, facing toward Effie but not looking at her, pursing his lips. It was atense moment; at least for us hum an observer. Finally, Effie ended the standoff with a series of sharp cough grunts.