Black panthers are more common south of Malaysia’s Isthmus of Kra than anywhere else in the world. (Photograph: Rimba)

Everybody knew Bagheera, and nobody dared to cross his path; for he was as cunning as [the golden jackal] Tabaqui, as bold as the wild buffalo, and as reckless as the wounded elephant. But he had a voice as soft as wild honey dripping from a tree, and a skin softer than dawn.

—Rudyard Kipling, The Jungle Book

Bagheera is a black panther who serves as friend, protector and mentor to Mowgli, the feral child protagonist of The Jungle Book. Does this black cat of dark rainforests exist outside Kipling’s tale?

Reuben Clements, co-founder of the Malaysian non-profit Rimba (jungle in the Malay language), has found the cat’s hideout.

Clements, who is also a field conservation associate with the international wild cat organization Panthera and Seattle’s Woodland Park Zoo, and his team have been tracking black panthers on the Malay Peninsula south of the Isthmus of Kra. There almost all panthers, or leopards, are black. Nowhere else in the world are there as many black panthers.

Finding black-as-night animals in a dense jungle isn’t easy, however. The panthers’ color obscures the spotted pattern common to all leopards, making it almost impossible to identify individual panthers.

Even with the help of camera traps – cameras wired on trees and left to record passing animals, writes Roland Kays in Candid Creatures: How Camera Traps Reveal the Mysteries of Nature – it’s a tall order to discern one black panther from another, let alone estimate the animals’ population size.

To study the panthers, Rimba scientists embarked on a project called Black Cloud. It would turn out to be as challenging as the jungle itself.

During the daytime, black panthers are indistinguishable on camera trap images. But with an ingenious trick, Rimba biologists rigged the cameras to detect individual panthers’ spots. That allowed the scientists to come up with a black panther population estimate for one part of the Malay Peninsula.

The effort is none too soon. The panthers’ rainforest habitat is fast disappearing, lost to timber operations that fell rainforest trees standing in the way of oil palm and rubber plantations.

To find out more about black panthers south of Kra, I caught up with Clements as he came out of the rainforest. He kindly answered a few questions.

Why are black panthers black?

Their color comes from a genetic mutation that causes an overproduction in the dark pigment melanin, which results in black fur coats.

What’s the difference between a black panther and a black leopard?

The term black panther refers to any melanistic [dark-colored] individual in the cat genus Panthera. In Asia, the term black panther refers to a black leopard. In the Americas, a black panther is usually a black jaguar.

Why is the Malay Peninsula important to black panthers? Does being black give the panthers an advantage in a dark jungle habitat?

The Malay Peninsula is home to the largest population in the world of black panthers. Some believe that black panthers are better concealed than lighter-colored leopards in the dense canopies of the region’s rainforests. Therefore, black panthers are more effective at stalking prey.

Why are black panthers common on the peninsula, but nowhere else?

No one really knows. Apart from the camouflage theory, another theory is that a leopard population crash in the region may have left a few surviving individuals that, by chance, happened to be black. This population crash would have created what’s called a founder effect, whereby the genes of these few individuals, or founders, would have been passed on to their offspring. But I think camouflage is the most likely reason.

How significant is the ecological transition zone that exists at the Malay Peninsula’s northern end, the Isthmus of Kra?

The Isthmus of Kra, which is only 44 kilometers [27.4 miles] long at its narrowest point, is where a transition between Indochinese and Sundaic fauna occurs, linked with a change from moist deciduous forest in the north to wet evergreen rainforest toward the Malay Peninsula in the south. North of the isthmus, there are more spotted leopards, and south of it, more black leopards, or panthers.

Why did you and your colleagues choose camera traps to estimate the panthers’ abundance on the peninsula?

You need lots of luck to see a panther in the rainforest! That’s why scientists need to place hundreds of camera traps that run 24 hours a day, 7 days a week, in the panthers’ habitat. When an animal walks past a camera trap, its body heat and movement trigger the camera trap to snap photos.

How many black leopards live in your study area?

Through the camera trap data, we were able to get an estimate of population size, which we believe is three black panthers per 100 square kilometers [38.6 miles].

Was any special camera trap technology needed to record black panthers on camera trap photos?

Yes, we needed the “technology” of sticky-tack [adhesive putty]! The camera traps take color photos of panthers when their sensors detect certain light levels.

When there’s low light, the sensors tell the camera traps to release bursts of infrared light, which illuminate black panthers’ spots. We needed to place sticky-tack on the light sensors to trick the cameras into believing it was dark even in daylight, so the infrared sensors would fire all day long. Then we could detect the spot patterns of individual panthers in a dense jungle, letting us see how many panthers there are.

What threats do the Malay Peninsula’s black panthers face?

Habitat loss and poaching are the biggest threats to black panthers. They’re also the main threats to the region’s other big cats – tigers and clouded leopards. For them and all the species of the jungle, we’re very concerned about the loss of rainforests to oil palm and rubber plantations.

What’s next in your research on black panthers?

We’re focusing on monitoring black panthers’ population trends, and assisting the Malaysian government in improving rainforest protection programs and anti-poaching law enforcement efforts. The cats’ coats are unfortunately popular with poachers. A highway also bisects an area known as the Kenyir Wildlife Corridor, where many black panthers live. We’re working to set aside this wildlife corridor as a protected area.

Why is your organization named Rimba?

We’re Rimba because our research contributes to rainforest protection. And because we all need a jungle out there.

For more about Rimba, please see: https://rimbaresearch.org/.