By K. Ullas Karanth, Director for Science-Asia at the Wildlife Conservation Society
Tigers are the largest of all living wildcats. Over the course of two million years, nature fine-tuned them as master predators through a trial-and-error process we call Darwinian evolution. Hunting alone, a tiger can take down prey four to five times its own size. While studying wild tigers over a quarter century I have tried to learn how they locate, stalk, ambush, subdue, and kill their prey—typically deer and wild pigs. Occasionally tigers kill calves of elephants and rhinos. However, what intrigued me most was how a lone tiger can subdue gaur, the largest wild cattle species in the world. These muscle-bound beasts, which look like they are on steroids, are three to four times heavier than the tiger. Their menacing horns can lethally impale a tiger; a well-placed kick can shatter its skull. A disabled tiger is as good as dead in the merciless jungle: Its certain fate isstarvation to death. Why, then, do solitary tigers indulge in such risky predation? The dramatic video above is from Bandipur Tiger Reserve in India, and it unveils how tigers attack such a large, dangerous quarry.
After examining hundreds of tiger kills, I had concluded that all successful gaur hunts would begin with the tiger launching a lateral sneak attack. Then it would grapple the massive prey down to the ground, while trying to deliver a killing bite to its neck. The tiger would thus try to stay out of harm from dangerous horns and flailing hooves. However, the tiger in the video chose to launch a potentially suicidal head-on charge!
Instead of pulling the female gaur down, he manipulates her neck with his powerful forelimbs and clamps down his vice-like jaws around her throat. Plunged in by the tiger’s powerful jaw muscles, his four 76 millimeter (three inch) dagger-like canines bury deeply into her throat. The tiger then nimbly gets back on his feet, still facing the gaur. By tugging mightily in “reverse gear” he ensures her lethal hooves are helplessly grounded, and sharp horns pushed away from him. The tiger waits, almost calmly, jaws firmly locked in place, steadily choking the victim. Within three minutes the gaur topples, strangled to death. This tiger made neither a sneaky flank attack nor wrestled the prey down. His predatory skill makes the violent act seem almost peaceful.
Although the gaur cow appears emaciated, she is still two to three times heavier than the 200-kilogram (440 pounds) cat. Obviously, this male tiger has mastered a specialized technique of subduing a stronger opponent, just as a champion wrestler would. I was curious: Who is this champion tiger?
As a researcher with the Wildlife Conservation Society (WCS), the jungles of Bandipur-Nagarahole have been my turf. I have assessed tiger and leopard populations here since 1991 using automated camera traps. The unique differences in their stripe patterns have helped me identify over 750 tigers so far, and their images now reside in my photographic database. Of course, not all of them are alive now.
Within an hour of getting their hands on this new video, the smart WCS research team zipped through the photo database using the pattern-matching algorithm EXTRACTCOMPARE. Years ago, a quietly brilliant British statistician Lex Hiby sought my collaboration when he developed this software. Quicker than it will take you to read this article, we identified the killer!
This tiger bears the ID number BPT-222. He was first photo-captured on March 16th, 2009 in Hediyala forest at the center of Bandipur Reserve, 30 kilometers (25 miles) away. Based on his size I estimated his age then at 18-24 months. Typically, sub-adults like him disperse away from their mothers’ range, trying to establish their own territories. By December 2009, BPT-222 had found his niche in the heavily visited tourism zone of Bandipur Reserve.
In collaboration with the Karnataka Government, I sample this tiger population using camera trap surveys for 30 days, every year. My objective is to estimate tiger numbers as well understand factors that drive population changes. By now, BPT-222 has been snapped in our camera traps for four years in succession. He was also photographed by tourists, some of whom share their images with me. BPT-222 has obviously reached a prime condition by gaining bulk and strength on a plentiful diet of beef, pork, and venison. He is also recognized as “Raja” (king) by local tour guides. In four years I got 33 photographic-captures, which helped me map a part of his territory while he perfected the art of hunting gaur.
Yet, I feel some trepidation. From 1990 to 1996, while doing the very first radio-telemetry study of tigers in India, I followed a young, rather obese male tiger nicknamed Das in honor of our portly camp cook. Das had also specialized in hunting gaur. Radio-tracking Das on foot one morning, I blundered close to a gaur cow, which he had apparently badly mauled. The wounded gaur angrily charged me, and I barely managed to escape. Later that night Das killed and ate her.
My camera trap research shows that even in Bandipur-Nagarahole’s protected population, about 20 percent of tigers are lost every year. Tigers die in conflict with humans or occasionally from poaching on the edges of Reserves, but more often than not they die fighting other tigers over mates, kills, or territories. Occasionally tigers also die from injuries sustained while hunting potentially dangerous prey.
One day in October 1991, after two years of radio-tracking Das, I homed in on his signals in the remoteness of his 50-square kilometer home range only to find his week-old, decayed carcass. Investigation of the flatted bushes, trampled grass, and huge hoof prints of a gaur at the site revealed that, for once, his predatory skills had failed Das. His addiction to hunting gaur had finally rendered the magnificent cat into a mere mortality statistic. As I watched the video, I hoped BPT-222 would be luckier.
The forests of Bandipur-Nagarahole and adjoining reserves today harbor possibly the largest viable tiger population in the world. Although many wild tiger populations are succumbing to human greed across Asia, at least here in Karnataka we have solid proof that generations of wild tigers have thrived as a result of tireless efforts by the government, conservationists, and researchers. I personally witnessed this population recover from a handful of tigers in the 1960s to over 300 animals now. I am cautiously optimistic that this tiger super-population will continue to thrive.
The unknown person who shared this stunning slice of the champion predator’s life deserves our thanks. I speculate whether BPT-222 inherited his special skills from an ancestor like Das. I hope, long after he joins his ancestors in tiger heaven, his progeny will continue to hunt in these magical jungles.