vegetarian diet At four months old, Harapan would feed under the watchful eye of his mother, Emi.
The more she learned, the more the challenges seemed to multiply. “It’s a very complicated species,” she told me one afternoon in her office, which is decorated with shelves full of wooden, clay, and plush rhinos. Rapunzel, the female from the Bronx Zoo, turned out to be too old to reproduce. Emi, the female from Los Angeles, seemed to be the right age but never seemed to ovulate, a puzzle that took Roth nearly a year to solve. Finally she realized that Sumatran rhinos are what’s known as induced ovulators: they need to be in close proximity to a male a slowbefore they release to-reproduce species an egg. Roth began to arrange carefully like the Sumatran monitored “dates” rhino is down to its between Emi and Ipuh. Very soon, last 100 individuals, Emi got pregnant. there just aren’t Then she lost the pregnancy. She many options left. conceived again, and the same thing happened. This pattern kept repeating, for a total of five times. Emi got pregnant again in the spring of 2000. This time, Roth put her on liquid hormone supplements, which the rhino received in the form of progesterone-soaked slices of bread. Finally, the following year, Emi gave birth to Andalas, a male. Three years later, she gave birth to Suci, and three years after that, to Harapan. (Emi died in 2009.) Just before Andalas reached sexual maturity, he was shipped to Sumatra, to a captive breeding facility in Way Kambas National Park, which
5 4 onearth
up to then had failed to produce any pregnancies. In 2012 Andalas fathered Emi’s grandson, a calf named Andatu. The three captive-bred rhinos born in Cincinnati and the fourth in Way Kambas clearly don’t make up for the many animals that died along the way. But they are just about the only Sumatran rhinos born anywhere over the past three decades, which is why Harapan has been brought here to mate with his sister.
ery big animals are, of course, very big for
a reason. At birth, Harapan weighed 86 pounds. Had he been born on Sumatra, he might have fallen victim to a tiger (though nowadays Sumatran tigers, too, are critically endangered). But probably he would have been protected by his mother, and adult rhinos have no natural predators. The same goes for other so-called megaherbivores; full-grown elephants and hippos are so large no animal dares attack them. Such are the advantages of being oversize—what might be called the “too big to quail” strategy—that, in evolutionary terms, it would seem to be a pretty good gambit. Indeed, until what might, geologically speaking, be thought of as recent times, the earth was full of Brobdingnagian animals. Toward the end of the last ice age, Europe had aurochs and cave bears and woolly rhinos. (DNA analysis has shown that Sumatran rhinos are the woolly rhino’s closest living relatives.) North America’s behemoths included mastodons, mammoths, and Megalonyx jeffersonii, a ground sloth that weighed nearly a ton. South America had its own gigantic sloths, as well as Toxodon, a genus of mammal with a rhinolike body and a hippo-shaped head, and glyptodonts, relatives of armadillos that in some cases grew to be as large as a Fiat 500. Australia was home to diprotodons, a group of lumbering marsupials