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Updated May 1, 2019 – With fewer than 70 individuals left worldwide, the Javan rhinoceros is thought to be the rarest large mammal on earth. Researchers funded by Morris Animal Foundation are in a race against time to protect the health of the remaining animals and give them a chance at population recovery. What seems to be standing in their way is a deadly parasite spread by a common fly.

Until the late 19th century and early 20th century, Javan rhinos existed from northeast India and the Sundarbans, throughout mainland Southeast Asia, and on the island of Sumatra. Illegal wildlife trade, natural disasters, invasive plant species and reduced genetic diversity chipped away at the population. The last Javan rhino living outside of Java, in Vietnam, was killed in 2010 by poachers. Now, disease is posing a significant threat to the species.

Tabanid flies, which include horse and deer flies, are found all over the world, including the Ujung Kulon National Park in Java, Indonesia, home to the last remaining population of Javan rhinos. From previous research, scientists know these flies are helping spread the parasite that causes hemorrhagic septicemia – an acute, highly fatal form of pasteurellosis common in local water buffalo populations – to the critically endangered Javan rhino population.

A Morris Animal Foundation-funded research team, wildlife managers, and local villagers in and around Ujung Kulon National Park have been collaborating in a desperate effort to save the Javan rhinoceros. Previous Morris Animal Foundation-funded research expanded knowledge about hemorrhagic septicemia. As a result, local government officials implemented a free vaccination program for livestock. This vaccination program helped reduce the risk of disease transmission from the water buffalo to Javan rhinos and other endangered animals living in the park.

However, the research team realized that more work needed to be done to save this fragile rhino population, the most endangered of the five rhino species. With continuing support from the Morris Animal Foundation, researchers currently are focusing their efforts on the exact role the tabanid fly plays in disease transmission in an effort to improve conservation strategies. Scientists also are working to understand the basic biology of these important disease vectors, much of which remains unknown.

Morris Animal Foundation has a long-standing commitment to preserving the health of endangered wildlife, including the Javan rhinoceros. The foundation has funded studies that have helped many endangered species, including African elephants, cheetahs and mountain gorillas, not only survive but thrive. Thanks to support from our generous donors, we have been able to fund new studies that may help save the Javan rhino, too.