Time and space are running out for the Javan rhinoceros — possibly the most endangered mammal in the world.
There are fewer than 60 left in the wild — almost all in a single Indonesian national park — and numbers appear to be declining for the first time in decades because of low birthrates, said Christy Williams, the World Wildlife Fund's Asian rhino specialist.
"We need to take immediate, urgent action to try to move some of these rhinos to another suitable site, either on Java or Sumatra island," he said Friday. "If we don't act quickly, I think we could lose this population."
The Javan rhino can weigh 5,000 pounds and measure more than 10 feet in length. Conservation groups say it is the world's most endangered mammal.
About 50 live in Ujung Kulon National Park, but it appears that only three of the females are breeding continuously, said Adhi Rachmat Hariyadi, who leads WWF-Indonesia's project in the park.
As a result, an average of one calf is born every year — near to the number of animals dying, and four times fewer than would be needed to sustain a healthy, growing rhino population, he and others say.
Williams said the park may have reached the maximum number of rhinos it can support and the animals may also be struggling to compete for scare resources with growing populations of wild cattle.
The government is working with conservation groups to find a suitable second site for the Java rhinos, which would help protect them from catastrophic events like disease or natural disasters, Williams said.
Researchers say a smaller population of Javan rhinos in Vietnam does not appear to be breeding anymore.