Suzy had spent most of her life with humans. She had had no opportunity to observe her own mother taking care of younger sisters and brothers. It was quite possible that she would show no interest in her baby. Unk was a further complication. Chimpanzee and gorilla fathers play no role in raising their children, but gibbon fathers do. Unk had grown up outside a normal siamang family, and had had no chance to learn how to be a father. It was possible that he would try to harm the baby. So, even if Suzy proved to be as good mother, the baby might have to be taken from her. On July 10, 1962, after a gestation period of 230 days (seven-and-a-half months), the baby was born. Suzy gave birth on a shelf along the back wall of the enclosure, picking a safe and secluded spot high in the air, as a siamang mother would do in the jungle. She behaved calmly and expertly, as if she had witnessed a hundred births. Unk watched protectively, making no attempt to interfere. The newborn baby was unbelievably tiny--the primate keepers estimated its weight at six ounces--less than half a pound. It had almost no hair, just a patch of black fuzz on the top of its head. The keepers could not help but think that this was a pretty pathetic looking little creature. Nevertheless, the newborn siamang was alert and bright-eyed, and appeared to be in good health. No humans were permitted inside the cage for fear of upsetting Unk and Suzy. Everyone wanted to encourage the siamangs to take care of their child, and the best way of doing that was to leave them alone for a few weeks.
			Suzy proved to be an excellent mother, caring for her tiny infant calmly, and with great gentleness. She seemed confident and happy as she nursed the baby, groomed and cuddled it. In the first few weeks of life, the baby was too small and weak to leave Suzy, so there was little for Unk to do in his new role as a father. Still, he behaved protectively toward his family and seemed interested in the baby. Any fears that Unk would be jealous of the infant or try to harm it proved unfounded. Naturally, the members of the zoo staff were very excited about the siamang baby. And so were the people of Milwaukee. At last, the press had a ready-made news story about the siamangs. Reporters wanted all the facts about the infant. Was it a boy or a girl? What was its name? Not wanting to disturb the siamang family, the zookeepers had not been able to examine the baby. They couldn’t tell if it was male or female, and so they thought it best to wait until it was older to name it. And of course it didn’t matter to Suzy and Unk if their child had a human name. But it did matter to the public. So the keepers decided to name the baby Mark.