A leopard cannot change its spots, and that is what may save those that inhabit Peninsular Malaysia.
As every leopard coat is unique, conservationists can keep track of the wild cats by identifying them through their pattern of spots. The cats are photographed when they trip camera traps.
But researchers had not believed they could track Malaysia's leopards in this way because they are mainly black. In 2010, however, scientists studying footage from camera traps discovered that the black cats - also called panthers - had spots that were illuminated by the infrared flash.
It turned out that a pigment in the cats' coats , eumelanin, transmits longer wavelengths of light such as infrared, Mr Gopalasamy Reuben Clements, co-founder of the Malaysian jungle conservation organisation Rimba, told livescience.com.
The researchers adjusted the cameras so that the infrared flash would fire every time they were tripped, day or night. With the new images, Rimba has estimated that there are three leopards for every 100 sq km of Malaysian jungle.
Thanks to serendipity, it might be the first time anyone knows this.