BEHIND THE HORN THE ABCS OF THE MIGHTY By Karyl Carmignani Photos by Ken Bohn STAFF WRITER SDZG PHOTOGRAPHER

12 ZOONOOZ MAY 2015 he rhinoceros is the second- of which is which. The white rhino is the leaving two parallel foot skids through the largest land , behind largest, tipping the scales at 4,000 to 5,000 pile as a form of communication. the elephant. These stocky, pounds and standing 5 to 6 feet tall at the Land Rover-sized vegetarians shoulder. It has a long forehead, a muscular Rising from the Ashes once numbered over 500,000, bulge (called a nuchal hump) on the top of "e southern white rhino has fared much but they have been reduced to its neck, and holds its head low while rest- better than its northern brethren, which about 29,000 in recent years, ing. But the best way to tell them apart is also have become functionally extinct with only Tlargely due to humans’ appetite for their what keeps them out of each other’s way at five individuals remaining. The southern signature appendage: the horn. Of the !ve mealtime: mouth shape! The white rhino white rhino, found primarily in South Af- rhino species, one is a conservation success has a wide, %at upper lip for mowing grass, rica, had been relentlessly hunted to near story (southern white), three are critically while the black rhino has a hooked, prehen- in the early 1900s. A surviving endangered (black, Sumatran, Javan), and sile lip for grasping and browsing on trees population of 100 was rounded up and pro- one is listed as vulnerable (greater one- tected in a national park in South Africa. horned), according to the International Today, southern white rhinos are a conser- Union for Conservation of Nature (IUCN). vation success story, as their numbers now "e current rate of poaching is unsustain- exceed 20,000. However, rampant poaching able for all rhinos. Subspecies of black and remains a chronic threat. Javan rhinos have already slipped into ex- tinction. Northern white rhinos are hang- The Mysteries of Asian Rhinos ing on by a !ngernail, with only !ve indi- Of the three rhino species surviving in viduals left, including Nola at the Safari Asia—Sumatran, Javan, and greater one- Park. For both “splitters” and “lumpers” horned—only one is showing conserva- of species and subspecies, the downward tion recovery while the other two are on trend is heartbreaking. the cusp of extinction. The greater one- With all the brouhaha about rhino horn, horned rhino has risen from the critically what exactly is it made of? Turns out, rhino endangered dust: in the 1900s, its numbers horn is made of keratin like our hair and !n- plummeted to about 200 , but today gernails, with deposits of calcium and mela- 3,330 animals live throughout India and nin in the core, so it is similar to horse hooves Nepal. While reintroduction projects have and turtle beaks. Scientists say the calcium MINDEN PICTURES begun, poaching and habitat loss remain a makes the horn stronger while the melanin looming threat. Will its thick, armor-like protects it from the sun’s UV rays. Rhino folds of skin ward o$ extinction? horns tend to curve backward toward the an- "e most threatened species is the solitary imal’s head because the keratin in the front Javan rhino, numbering about 60 individu- grows faster. "e outer layers are somewhat Above: The Javan rhino is critically als in one national park in Java, Indonesia. so# and can be worn down a#er years of use. endangered. Left: Black rhinos have a According to the Asian Rhino Project, work Rhinos inhabit savannas and forests in hooked, prehensile lip ideal for browsing has begun to expand the rhinos’ habitat by tropical and subtropical regions. Africa has on leaves. They live in Africa with the relocating illegal human settlers; eradicat- white rhino. two species, both with two horns: the white ing the arenga palm, an invasive plant that rhino Ceratotherium simum and black rhi- prevents the undergrowth (rhino food) from no Diceros bicornis. "e Asian rhinos are and shrubs. "e two species do not compete flourishing; and replanting suitable rhino the greater one-horned Rhinoceros unicor- for the same resources, since one is a grass greens. "e Javan rhino sports one horn, and nis and Javan rhino R. sondaicus, both with grazer and the other a tree trimmer. the female’s horn is virtually non-existent, one horn, and the Sumatran rhino Dicero- It is thought that the white rhino’s name which could discourage poaching. Sadly, the rhinus sumatrensis, with two horns. was derived from the Afrikaans word “weit,” last Javan rhino in Vietnam was felled by a meaning wide, to describe its mouth. Black poacher’s bullet in 2010. African Rhinos: Read My Lips rhinos probably earned their name from "e hairiest rhino is the only two-horned Before you head o$ on an African safari to their wallowing lifestyle and the dark mud rhino in Asia: the Sumatran. It is also the test your rhino knowledge, note that white on their skin. Both can produce 50 pounds most petite, weighing in at about 1,320 to rhinos aren’t white and black rhinos aren’t of dung a day, and both species scrape the 2,000 pounds and measuring 3.3 to 5 feet tall black. Luckily, there are other telltale signs dung pile with the rear feet, %inging it and at the shoulder. "ey are more closely related

SAN DIEGO ZOO GLOBAL SANDIEGOZOO.ORG 13 to the now-extinct woolly rhino than the other four rhino species. Only the Sumatran and greater one-horned rhi- nos have canine teeth, which they use to slash and gouge at enemies. Making It through History The rhinoceros is an odd-toed ungu- late known as a perissodactyl, related to , horses, and zebras. "e earliest known odd-toed, rhinoceros-like mam- mal appeared during the middle of the epoch (56 to 33.9 million years ago) and was the size of a large dog, with hooves, plant-eating dentition, and no horns. "ree families of rhinos evolved in the late Eocene: Hyracodon- tidae (running rhinos), Amynodontidae (aquatic rhinos), and ancestors of mod- ern rhinos, Rhinocerotidae. "is com- 1 pact variety was distributed throughout the world, including North America. Lip shape, horn number, and the It died out there about 4 million years fur factor help tell who is who ago, while the jumbo-sized, two-horned 1 Southern white (wide-lipped, largest woolly rhinoceros %ourished in Eurasia species) 2 Sumatran (small and hairy type). up until the last Ice Age. It went extinct 3 Black rhino (hooked lip, two horns) 4 Javan (single horn, critically endangered) around 12,000 years ago, most likely 5 Greater one-horned rhino (layers of thick due to humans hunting it for its meat skin resemble armor, one horn). and thick fur pelt. Of the remaining rhinos, the great- er one-horned rhino appears to be the oldest modern lineage, followed by the Sumatran rhino a million years later. The new species on the block—geo- logically speaking—are the African rhinos, which appeared about 17 mil- lion years ago. DNA evidence shows white and black rhinos diverging from a common ancestor about 2 million .5 years ago, while fossil evidence in- dicates an earlier departure of 7 to 8 million years ago. .2 All in all, rhinos have been quite successful, grazing and browsing their way across history virtually unboth- ered by predators—until humans and their high-powered weapons arrived on the scene. Now it is up to humans to change their ways and make the right decisions to keep the remaining rhinos safe, so these magni!cent ani- mals will still share the planet with us .3 .4 into the future.

14 ZOONOOZ MAY 2015