It’s World Rhino Day today. To celebrate and discuss, Dr Emma-Louise Nicholls (Deputy Keeper of Natural History of the Horniman Museum and Gardens) shares her insider knowledge and experience in rhinoceros conservation, after her recent return from the Sumatran Rhino Sanctuary in Indonesia.
The Sumatran rhino’s problems began the moment someone, a name now lost to history, first decided rhino horn should be used as a medicinal ingredient. This idea was passed down from generation to generation until, over 2,000 years later, the use of rhino horn is deeply ingrained in people’s minds and cultures. These ancient remedies, now commonly referred as ‘Traditional Chinese Medicine’, are still used today, primarily in China and Vietnam. Contrary to popular western belief, rhino horn is not (ironically- until very recently) used as an aphrodisiac, but rather to treat a large number of ailments including fever, hallucinations, and headaches.
Rhino horn is largely made of keratin, however; and you’d feel just as better if you ground up and swallowed your own fingernails. Nevertheless, hunting these animals for their horns decimated Sumatran rhino populations throughout Southeast Asia and, as the issue of habitat loss also began to raise its ugly head, the combined impact of these two sustained pressures led to the collapse of wild populations. As a benchmark; in the 1980s it was estimated there were around 1,000 Sumatran rhinos in the wild. In 2017, that number is estimated to be around 100.
Until recently, these remaining wild populations were split between Indonesia and Malaysia. Unfortunately, there are now only two known individuals of the Bornean rhino left (a different subspecies), which live in a private research facility in Tabin Wildlife Reserve in Sabah, Malaysia. On a positive note, these two remaining individuals are a male and female; generally accepted as the two primary requirements of a breeding programme. However, even if intensive breeding of their would-be sibling-offspring wasn’t an evolutionary no-no, in a cruel twist of fate Sumatran rhinos that haven’t produced offspring by a certain age often develop cysts in the uterus and can become unable to conceive anyway. As is the case for Iman, the last known remaining female Bornean rhino.
The largest known wild Sumatran rhino populations, holding on with all 12 toes in Indonesia, are now restricted to three national parks, all on the island of Sumatra. Having separate populations is good for genetic diversity, and if a natural disaster or disease should wipe out one population then the species will still persist due to those that were isolated from it. If, for example, a large tsunami hit the northern edge of Java (heaven forbid) where Ujung Kulon National Park is located, it could well wipe out the entire Javan rhino species, as there are no other populations anywhere in the world. On the other hand, if numbers of Sumatran rhino are so thin in each of the three parks that male and female rhinos won’t find each other, then short of joining Sudan on Tinder, making babies in the wild becomes exceptionally difficult, meaning perhaps bringing them together is the better option. Faced with this unenviable quandary, a lot of conservationists feel the answer is in a captive breeding programme with the aim of repopulating the wild habitat with captive-born rhinos.
Scientists find the key
The first known record of a Sumatran rhino to be born in captivity was in Calcutta, India in 1889. Although the specific details are irritatingly lost to history, rhino experts seem to feel there is enough evidence to substantiate the story. Nearly 100 years after India perhaps unintentionally made rhino history, the need for a captive breeding programme became urgent and so between 1984 and 1996, 40 of the approximately 1,000 Sumatran rhinos persisting in the wild at the time were captured (from both Indonesia and Malaysia) to form a worldwide collaborative captive breeding programme. The wild-caught rhinos were split up between Indonesia, Malaysia, Thailand, the United States, and the UK who all tried their hand at breeding these enigmatic animals.
Thirteen years later, the pitter patter of tiny rhino feet was still absent from zookeepers’ ears and so in 1997 scientists at Cincinnati Zoo led by Dr Terri Roth (Vice President of Conservation and Science, and Director of the Centre for Conservation and Research of Endangered Wildlife; CREW) turned to endocrinology and ultrasonography. A long and complicated story of science, frustration, grumpy rhinos, and no mating unravelled until Dr Roth and her team finally discovered that Sumatran rhinos are in fact induced ovulators. This means that a female won’t come into oestrus until she has had ‘special time’ with a male, after which, she obviously needs to gain in order to conceive. This was an exceptional breakthrough, and one that resulted in the first Sumatran rhino born in captivity in 112 years when Ipuh, one of the last three rhinos surviving from the original project initiated in 1984, successfully mated with a female called Emi, and with that a heavy hairy miracle was born. With all of their new found expertise in rhino romance, the CREW team managed to help Ipuh and Emi produce two more babies- a female called Suci in 2004, and a male called Harapan in 2007.
Meanwhile in Indonesia
As scientists in Cincinnati were working on unravelling the mysteries of the Sumatran rhino’s reproductive requirements, on the other side of the world the Sumatran Rhino Sanctuary was completed in Sumatra, Indonesia, and in 1998 opened its doors to its first residents; two females, Dusun and Bina, and one male, Torgamba. Two more females, Ratu and Rosa, arrived in 2005. Yet despite being spoilt for choice on the dating scene, Torgamba sadly wasn’t up to the task and the breeding programme appeared to be failing.
Fortunately for Sumatran rhinos, in 2007 Dr Roth and her rhino specialist team gave the programme’s first born male, Emi and Ipuh’s first calf Andalas – now six years old, to the Sumatran Rhino Sanctuary in a bid to save the day. It turned out to be worth their heartache as in 2012 Andalas became a first-time father and the number of Sumatran rhinos in the world went up by another one. One is a significant number when there are so few remaining, and Andatu, Andalas’s son, made history when he became the first baby rhino born at the SRS.
Andalas is obviously enjoying his new life as chief baby-maker as he and his ‘partner’, Ratu, successfully bred again and in 2016 had a girl called Delilah. By 2014, Harapan (Andalas’s younger brother, born at Cincinnati Zoo) became the only Sumatran remaining outside of Indonesia and Malaysia and so the Cincinnati team decided to let him follow in his brother’s footsteps and sent him too, to the SRS in Indonesia.
Hunting and habitat loss have decimated wild numbers of rhinos to a point where physiology is now their main problem (although the aforementioned issues also persist). The need for induced ovulation, as well as the fact that cysts can develop in the uterus if females remain unmated, both mean that with so few rhinos in the wild, many females are likely to become unable to conceive. The stability of wild Sumatran rhino populations remains in question and captive breeding programmes used to boost numbers in the wild seem to be the most viable way of increasing their numbers to a level where they’ll regularly be able to breed naturally in the wild again.
In 2017, now armed with an entire crash (the official, not to mention delightful, collective noun for rhinos) including both males and females, the Sumatran Rhino Sanctuary is on a path paved with hope and optimism. Andalas and his rhino team are undoubtedly working hard to produce more bundles of joy, and with the high levels of expertise and dedication witnessed first-hand at the SRS, there is definitely hope for the Sumatran rhino yet.
Visit the International Rhino Foundation website
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