Despite pregnancy loss, conservationists still hopeful for Sumatran rhinos

Two of the rhinos at the Sumatran Rhino Sanctuary in Way Kambas, breeding. Credit IRF

March 2010. Conservationists across the world are saddened by the loss of the first pregnancy of Ratu, a young female Sumatran rhino at Indonesia's Sumatran Rhino Sanctuary in Way Kambas National Park. Ratu and male Andalas, brought together through international goodwill and cooperation in an effort to save this critically endangered species, bred successfully in January, and a pregnancy was announced in February.

Ratu found in 2006
Ratu, born in Indonesia, wandered into a village just outside Sumatra's Way Kambas National Park in 2006. Andalas, the first of only three Sumatran rhinos born in captivity in more than 112 years, was born at the Cincinnati Zoo & Botanical Garden in 2001, grew up at the Los Angeles Zoo and was transferred from the L.A. Zoo to the Sumatran Rhino Sanctuary in 2007.

Not unusual for first pregnancy
Three years after Andalas' successful transition to the Sumatran Rhino Sanctuary, he and Ratu mated. The breeding followed months of gradual introduction by scent, sound, sight, and finally, physical proximity. An ultrasound revealed Ratu was pregnant in early February. However, recent examinations indicate that the embryo is no longer present.

"This is not unusual for a rhino's first pregnancy," said Dr. Susie Ellis, executive director of the International Rhino Foundation (IRF). "While we are saddened by this loss, the fact that we achieved a pregnancy confirms that our work with the Sumatran rhino breeding program is progressing. Ratu and Andalas are healthy and have produced one pregnancy, so we are optimistic that success will soon be achieved."

Just 200 Sumatran rhinos left alive
The Sumatran rhino population is estimated at approximately 200 individuals in the wild and 10 currently in captivity worldwide. Ratu and Andalas represent hope for a future generation.

"Our staff is disappointed, but the fact that we did achieve a pregnancy reconfirms our commitment to helping Ratu and Andalas succeed," said Dr. Dedi Candra, the sanctuary's animal collection coordinator. "We continue to learn more about the Sumatran rhino's breeding and gestation habits, which will help us manage Ratu's next pregnancy."

Dr. Terri Roth, director of Cincinnati Zoo's Center for Conservation and Research of Endangered Wildlife (CREW), applied her extensive training in reproductive biology to produce three Sumatran rhinos beginning with Andalas in 2001, utilizing hormonal assays and ultrasound techniques to determine the optimal time for introducing males and females.

"The fact that we achieved a pregnancy after only the third mating between Andalas and Ratu is still a victory. Emi, Andalas' mother, lost a number of pregnancies early in gestation before she carried one to term," said Dr. Roth. "Early pregnancy loss in rhinos appears to be fairly common, but we have the advantage of being able to draw on our experience with Emi to help Ratu sustain her next pregnancy."

The Sumatran Rhino Sanctuary
The Sumatran Rhino Sanctuary is a 250-acre complex built and funded by IRF. It is currently operated in partnership with the Rhino Foundation of Indonesia under an agreement with the Indonesian Ministry of Forestry. The sanctuary houses five rhinos that are part of an intensively managed research and breeding program aimed at contributing to the conservation of the species in the wild. The rhinos reside in large, open areas where they can experience a natural rain forest habitat while receiving state-of-the-art veterinary care and nutrition.

Captive breeding
"Captive breeding is one part of an integrated Sumatran rhino conservation strategy," said Dr. Ellis. "Our focus, along with our local partner, the Rhino Foundation of Indonesia, is to protect rhinos in the wild as well as to bolster the population through captive breeding. IRF also funds anti-poaching units in three Indonesian national parks. Thanks to those programs, there has been no rhino poaching in the last five years, and poaching of other large vertebrates which share rhino habitat has decreased significantly. Saving this species is a balancing act. We must care for the wild population and also try to breed as many animals as possible in captivity in order to save it."

Development of a viable and holistic program that involves captive breeding will provide insurance against the difficulties and uncertainties of protecting the Sumatran rhino in the wild. In addition, solid success with this species may provide a model for development of a similar program for the critically endangered Javan rhino, whose population is more stable but numbers no more than 50 individuals in the wild, and has no insurance population in captivity. Indonesia harbors two critically endangered rhino species, but with far less attention than African rhinos, under pressure from a 15-year high in poaching for horn, which is used in traditional Asian medicine as a fever-reducing agent.