By Erica Goode

New York Times

Leopards are reclusive and known for their ability to adapt, traits that have led some wildlife biologists to assume that the animals remained relatively abundant in the wild.

But a study published Wednesday suggests that leopards have lost as much as 75 percent of their historic range since 1750. At that time, the big cats roamed over about 13.5 million square miles in Africa, Asia and parts of the Middle East. But that vast area has shrunk to about 3.3 million square miles, according to the study, conducted by a team of 14 scientists representing 15 universities and organizations, including the Zoological Society of London, the Wildlife Conservation Society, the Iranian Cheetah Society, NationalGeographic and Panthera, the global wildcat conservation organization.

The study, which appears in the journal PeerJ, is believed to be the first to assess the leopard’s status globally across nine subspecies and won immediate praise from other scientists for its scope and detail.

Partly on the basis of the findings, the cat specialist group of the International Union for Conservation of Nature has recommended that the leopard (Panthera pardus) be reclassified on its Red List of threatened species as “vulnerable,” indicating that stronger conservation efforts are needed, said Andrew B. Stein, an author on the study who is a member of the group.

The species is currently listed as “near threatened,” with three subspecies classified as “critically endangered” and two others as “endangered.”

Luke Hunter, president and chief conservation officer of Panthera, said that the study’s findings highlighted the fact that many of the world’s most iconic animals are disappearing from the wild.

“Their trajectory is just the same,” he said. “Lions and tigers are faster to disappear than leopards, and yet it’s exactly the same process.”

Like lions, leopards have been threatened primarily by human activities, including the destruction of habitat; the hunting of smaller animals that leopards depend on for prey; revenge killings by farmers who have lost livestock; illegal trade in leopard skins and parts; and, to a lesser extent, trophy hunting in countries where it is allowed.

The researchers analyzed 6,000 records from 2,500 locations and more than 1,300 sources to map the leopard’s current and past ranges (1750 was picked as a starting point because it was before the beginning of the Industrial Revolution and the colonial era in Africa). The records included studies, reports, photographs and newspaper clippings.

Overall, the study found, the leopard’s range had decreased by 63 percent to 75 percent, with the difference representing areas where the data was less clear-cut. But of the nine subspecies, only three were represented in 97 percent of the cat’s current range.

Three other subspecies — the Arabian leopard, the North Chinese leopard and the Amur leopard, a shaggy cold-weather cat found in far eastern Russia — retained only 2 percent of their historic range, the researchers found. In large parts of Asia, including Southeast Asia and the Middle East, leopards had almost vanished. Only about 17 percent of the big cat’s current range was protected land.

Even in places where leopards still had expansive ranges, the researchers found, they were often fragmented, their habitat broken up by farms, villages or other human development.

That did not augur well for some leopard subspecies, which had only a few patches left, the researchers wrote. In general, the more clusters of dense population there are of a species, and the more “corridors” of land that exist, allowing animals to travel from one area to another, the more likely the species is to survive, they noted.

“This is a sophisticated and very comprehensive study,” said Tim Caro, a professor of wildlife biology at the University of California, Davis, who was not involved in the study.

Caro called the tiny pockets of leopards that the researchers found still existed “particularly depressing.”

“Without strong action by governments, their fates are sealed,” he said.

Theodore N. Bailey, a retired wildlife biologist and the author of a 1993 book, “The African Leopard: Ecology and Behavior of a Solitary Felid,” said the study was “the most comprehensive and detailed analysis of the status and distribution of the leopard to date.” He noted that, although the leopard could adapt to a wide variety of landscapes, from rain forest to desert, and to different type of prey, the study found that its loss of range was greater than that of other predators.

“I think the biggest threat to the leopard on a global scale is that it’s been just under the radar,” said Philipp Henschel, the lion program survey coordinator for Panthera. “Nobody really cared about the leopard because everybody assumed they were really abundant and widespread.”

That neglect was reflected in the scientific literature. Although scientific reports had increased steadily since 2000, the new study found that of 330 articles on leopards published from 2000 to 2015, 69 percent dealt with only two subspecies. Three subspecies had fewer than five research articles each devoted to them.

Henschel said that the subspecies that were listed as critically endangered “could be lost in the next five years or so.”

“We really have to act urgently,” he said.