Within the last ten years the Sumatran rhino (Didermoceros sumatrensis) population has dropped 50%, and only 200 to 300 individuals exist. Due to habitat loss and poaching, the Sumatran is critically endangered. There are only four Sumatran rhinos in captivity, three at the Cincinnati Zoo, named Andalas, Emi and Ipuh and one at the Bronx Zoo named Rapunzel. Sumatran rhinos are solitary, although males and females are seen together during courtship. Their native habitat is dense tropical forest and mountain moss forest, and they are extremely dexterous, being able to climb "almost sheer cliffs." Sumatrans are reclusive and tracking them in dense forest has proven difficult, so little is known about their behavior. They are the smallest living rhino, standing 3-5 feet (0.9 - 1.5 meters) tall. The Sumatran rhino is the oldest living species of rhino, and is a descendant of the wooly rhinoceros. It is thought that they have remained unchanged for the last 2 million years. Sumatrans are covered in long course, reddish-brown hair, with tufts on their ears.

The Sumatran's communication is very unlike that of other rhino species. White rhinos communicate rarely, and blacks and Indians have interesting "moos" and "trills." However, none of these species produce vocalizations constantly, nor are they songlike as the Sumatran's are. There has never before been a scientific study performed on Sumatran vocalizations, in fact, few persons have ever even heard these creatures. Because the outside enclosures at both the Cincinnati zoo and the Bronx zoo are set back from the public walkways, and Sumatrans are basically "shy", few individuals except the keepers and those that work closely with them, have ever heard the Sumatran's beautiful "songs."

Hear some sounds of a Sumatran rhino

In novel research performed by Fauna Communications, three adult Sumatran rhinos, housed at the Cincinnati Zoo, were recorded from 1 - 3 meters. Two Statham Radio microphones and two TCD-D8 Sony DAT recorders recorded from 9 Hz to 20 kHz. Analysis, including power spectrum, spectrographs and filtering were performed using National Instrument's Polynesia. The rhinos proved to be extremely vocal and produced signals almost continually. The rhinos would even produce vocalizations when they were eating. Distinct calls, including several types of "eeps," 70 Hz - 4000 Hz (57-92 dB); "whales," 100 Hz - 3200 Hz (87 dB); and "whistleblows", 17 Hz - 8000 Hz (100 dB) were discovered. The "whistleblow" has high dB infrasound that would be advantageous for use in the rhino's forest habitat.

Hear various vocalizations of a Sumatran rhino

Hear the sounds of a humpback whale

After recording and analysis, since some of the vocalizations sounded so similar to whales, a scientific recording of Humpback whale song was procured and analyzed. It became clear immediately that some Sumatran rhino vocalizations sound similar to, and resemble (under analysis) some humpback whale signals. Fauna Communications contacted several paleontologists, one whom stated that the similar songs (rhino and whale) could be convergent evolution, or be what is known as an ancestral song. Sumatrans are perissodactyls, odd-toed ungulates. There is some research that indicates that rhinos may be a sister group to whales.

After the conclusion of this study Emi from the Cincinnati zoo gave birth to a male, named Andalas. This is the first Sumatran rhino to be born in captivity for 100 years. Because of the critically endangered status of the Sumatran, it may be that protected environments will the only places that can keep this remarkable animal from becoming extinct.

"Can you speak rhinoceros? Of courseros, can't you?"
Dr. Dolittle

---

[ Lay Language Paper Index | Press Room ]