On May 23, a heavily armed gang of mask-wearing poachers descended on Karizanga National Park in the northeastern Indian state of Assam. By the time rangers found the intruders and opened fire, forcing the poachers to flee, one of the park’s rhinoceroses lay dead, its horn chopped off and a bloody hole left in its place.

It was the second rhino killed in less than a week at Karizanga, and at least the 18th rhino lost in Assam so far this year. All told, 156 rhinos have been poached there since 2006, more than one-third of which were killed in the past two years. The majority of the poaching occurs in the park, home to about two-thirds of the world’s population of Indian one-horned rhinoceroses. The largest of the five rhino species, they are targeted for their big, and valuable, horns, which are ground up and sold as “medicine” or hangover cures in China and Vietnam. Criminal syndicates in Asia drive much of the illegal trafficking.

Rhino poaching has been on a dramatic rise in India over the past few years, just as it has in southern Africa. More than 1,000 rhinos were killed in South Africa alone in 2013, a record high. South Africa is home to about 75 percent of all of the world’s rhinos, including both African species. (The most endangered species live in Java and Sumatra and have populations of fewer than 100 animals each.)

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Even as poaching increases in India, there is also cause for optimism. A paper published this month by Assam’s environmental ministry reveals that the population of Indian one-horned rhinos in the state has grown by 27 percent since 2006, hitting a modern-day high of 2,544 animals. This puts the population well on track toward the Indian government’s goal of 3,000 rhinos by 2020. (Smaller populations live in neighboring Nepal.)

That represents a tremendous success for conservation, said Barney Long of the World Wildlife Fund, pointing out that there were only about 200 Indian rhinos in the early 1900s. “I think this is a lovely story of conservation success, despite the hideous poaching crisis that we’re in,” he said.

“We know how to save rhinos,” he added. “You have to protect their habitat, and you have to protect the animals themselves.”

A third element involves moving the animals into new, safe habitats as their populations increase. “When rhinos get too dense of a population, they decrease their breeding rate,” Long said.

Assam has been effectively managing its rhinos by moving some of them out of Karizanga to other locations, and establishing populations in other, smaller parks—something WWF has actively supported—along with other efforts to protect the species.

“This means instead of breeding rates of 2 or 3 or 4 percent, we can be pushing 7 or 8 percent,” Long said. It also spreads out the risk by not placing all of the rhinos in a single location that poachers can target.

Long said Assam’s approach has been “very, very successful. Even though they’re seeing this uptick in poaching, they are still seeing a growth in rhino population.” The question remains, however, how much longer all rhino species can endure the continuing increase in poaching and rhino horn trafficking. “Pretty soon, if poaching continues, we’re going to see declines in populations,” Long said. “They can’t withstand it forever.”