Rhinoceros Undergoes Assisted Reproduction to Rescue Species from Extinction

News | Evolution

Conservationists are taking heroic measures to restore fertility to a three-footed Sumatran rhino, but it's unclear if this is a prudent undertaking

By Henry Nicholls and Nature magazine ?| May 30, 2012

Image: M. SIMONS/GETTY

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From Nature magazine

First, the vet inserts his arm in a shoulder-length plastic glove. Next, he grips an ultrasound probe and slides both arm and probe deep into the rectum of a 500-kilogram rhinoceros. All eyes of those present, including his, are on the ultrasound image on the laptop monitor nearby. As the vet moves the probe over the animal's intestinal wall, her uterus comes into view on the screen. Even to the untrained eye, it is clear that there is something seriously wrong: marble-sized cysts fill the space where there should be a smooth uterine lining. As if in acknowledgement of the fact, the rhino lets out a doleful moan.

This is Puntung, a Sumatran rhinoceros that is missing a foot as well as a working uterus. Yet the future of this species in Malaysian Borneo may rest on the hairy shoulders of this singular beast. If she is ever to reproduce, she will need Thomas Hildebrandt and his veterinary team from the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin to rescue her womb ? and then push the boundaries of rhino assisted-reproduction to new extremes.

According to the latest best guess, only 200?300 Sumatran rhinos (Dicerorhinus sumatrensis) may be left in the wild, split between three territories in southeast Asia: the Indonesian island of Sumatra, Peninsular Malaysia and the state of Sabah in Malaysian Borneo (see 'The remaining rhinos'). This perilous situation is a result of a devastating combination of habitat loss (mainly to create lucrative oil-palm plantations) and poaching (to feed the black market for rhino horn). Conservationists say that the species' small, fragmented population is now the biggest threat to its survival, with animals so sparsely distributed that they are simply unable to meet each other to mate. Because females that haven't mated when they are in oestrus can develop problems with their uterus, the rare encounters that do take place often come to naught. At best, rhino mothers take several years between pregnancies ? meaning that the birth rate in the wild is unlikely to keep up with poaching and natural deaths.

Drastic measures
This desperate situation has led conservationists in Sabah to a desperate conclusion: that the only way to maintain the rhino population here is to capture as many as possible of the remaining animals ? which may number as few as 30 ? and subject them to assisted reproductive technology. That includes scrubbing out the uterus of Puntung, and possibly techniques such as in vitro fertilization (IVF) and cloning, the likes of which have rarely been wielded in the name of conservation. ?Either we give up or we try to make every fertile rhino contribute to the future of this species,? says John Payne, executive director of the Borneo Rhino Alliance (BORA) in Kota Kinabalu, Sabah. ?The best way to do that is to bring them into fenced, managed facilities.?

Such a drastic attempt to rescue a highly endangered species has precedents. Conservationists have, through heroic efforts, wrestled species such as the Arabian oryx (Oryx leucoryx), the black-footed ferret (Mustela nigripes) and the California condor (Gymnogyps californianus) back from the brink of extinction by bringing all the remaining animals together, using artificial insemination to spread sperm and maximize genetic diversity, and keeping offspring alive through round-the-clock husbandry.

In the case of the Sumatran rhino, however, some conservationists worry that without a long-term strategy for reversing the environmental pressures that are killing them off, captive breeding alone can never restore the wild population. ?It's not a plan unless you've mitigated the threats that wiped them out in the first place,? says Alan Rabinowitz, chief executive of the wild-cat conservation group Panthera in New York city. Others are uncomfortable with throwing so much money and effort at a single species ? a single animal, in Puntung's case ? when the chances of success are so slim. ?One of the biggest challenges facing conservation today is our inability to step back and admit that there are animals that would take a little bit less work and a little bit less money but have the potential to survive for their genetic diversity into the future,? says John Fraser, chief executive of the New Knowledge Organization in New York city, a think tank and advocate of a triage response to species conservation. ?They may not be as charismatic, but quite frankly we have to admit that some species are not going to make it and it's really, really sad.?

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