In 2014, a team of the local Idu Mishmi people led by Dr Sahil Nijhawan placed cameras in the jungles of Dibang Valley, Arunachal Pradesh to understand the distribution of medium and large-sized mammals. After 20 months, when they started to look at the images captured, they saw something strange and unexpected. There were many pictures of differently coloured, medium sized cats — all of which were Asiatic golden cats.
This discovery has now brought out the fact that Dibang Valley in Northeast India houses the highest number of variants of any wild cat species in the world — six in this case! The study detailing it has been published in the journal Ecology.
This study formed part of a larger research focused on using ecological and anthropological approaches to understand human-wildlife interactions in Dibang Valley.
“We surveyed Idu Mishmi-owned and protected forests in Dibang Valley in collaboration with the local people. This is a novel methodology in which scientists and local people collaborate to co-produce knowledge. All my scientific publications are co-authored by my local Idu collaborators from different villages in Dibang Valley,” says Dr Nijhawan from Zoological Society of London and University College London, and lead author of the paper.
The local Idu Mishmi people of Dibang Valley believe that the golden cat, particularly darker melanistic morphs, are carriers of great powers and they observe a strict taboo on hunting all felines, including the golden cat.
Remember the black panther Bagheera from Rudyard Kipling’s The Jungle Book? Although black, he too is only a colour-variant of the Indian leopard. This phenomenon, when individuals have two or more colour variants, is called polymorphism. Many cats, like leopards, Asiatic golden cats, African golden cats, and oncilla, also benefit from polymorphism — they use it as camouflage to protect themselves against larger predators or to hunt.
Asiatic golden cats (Catopuma temminckii) are medium-sized wild cats found in Northeast India, Nepal, Myanmar, Bangladesh, China and Southeast Asia. They inhabit a wide range of habitats, from evergreen forests, scrub and secondary forests to high altitude mountains and hunt birds, reptiles and small mammals. In recent years, owing to habitat loss, their populations are decreasing, and they are now categorised as a ‘Near Threatened’ species.
Previous research has shown that in Dibang Valley, most of the species, including the golden cat, occur in high densities in community-owned forests. It is these poorly-studied community forests that would come under threat with plans to build more than 15 hydropower dams in the area.
The study found six different colour morphs among these cats — golden, grey, melanistic, ocelot (spotted), cinnamon and tightly-rosetted (a darker morph with tight rosette patterns). The study also marks the first discovery of the tightly-rosetted morph of the golden cats in the world.
Interestingly, researchers found that different colour morphs were found at different altitudes. At higher elevations, above 3,000 m, they found more morphs with patterns (ocelot and tightly rosetted) than at elevations below 1,700 m, where most morphs were of a single colour (cinnamon, golden or melanistic). The behaviour of these cats also varied with the colour variant.
The patterned and grey morphs were completely nocturnal, whereas the other single-coloured morphs were diurnal or active during the day.
“Researchers in the past had suspected that different morphs might show a preference for different habitats. This study is the first proof of such a preference,” says Dr Nijhawan. He also added that these colour morphs could provide different ecological benefits to the cats by making them highly adaptable in different habitats.
Researchers believe that the different coloured and patterned coats could help golden cats by providing camouflage and hunt various kinds of prey, such as reptiles and rodents in the low elevation tropical forests, and the Himalayan pikas at high altitude alpine scrub. They also suggest that the different coats could help them avoid competition from larger predators like tigers, leopards, dholes and clouded leopards, which are also found in the golden cats’ habitat.
“In an environment as competitive as the Eastern Himalayas, the golden cat has shown that adaptability is what you need to thrive. This would probably apply to other polymorphic species as well,” says Dr Nijhawan. So, does it mean that polymorphism exists where there is more competition and habitat diversity? “This case study of the golden cat gives us some indication of this. However, we would need to collect more data to test this hypothesis,” he adds.
The findings of the study also have important implications on the evolution of these cats.
“Currently, we believe that different morphs interbreed. However, if, for some reason, interbreeding stops, then it could be the beginning of splitting up into new subspecies or species,” concludes Dr Nijhawan, hinting at the excitement that studies in the future hold.
(The author is with Gubbi Labs, Bengaluru)