Why Sri Lanka is so good for Leopards - Article by Gehan de Silva Wijeyeratne.

Safari guide to big cat behaviour

Why Sri Lanka is so good for leopards

Big Cats are Big Business. The lions in the savannas of Africa, the tigers amongst ruined palaces claimed by the jungle in India, the Jaguars in the Pantanal, the livestock raiding Pumas in North America and the leopards brazenly hunting by day in the thorn scrub of Sri Lanka, are worth tens of millions of US dollars every year. They are the focus of an international safari industry. They are iconic; they have come to represent continents and countries. They are the football stars of the animal world. On a journey in the London Underground, I may be confronted with a wall poster of a Tiger advertising ‘Incredible India’ or a digital advertisement from British Airways with a leopard enticing the commuter to book a holiday to Sri Lanka. People love cats. The magic is bigger with the Big Cats, they enthral, mesmerize and entertain with whole TV programmes centered around them.

When I was commissioned to write Wild Sri Lanka for John Beaufoy Publishing, I realized that there was much in the scientific literature on the behaviour of wild cats, especially the big cats which translate into tourist dollars. But much of this information was not available in an easily digestible form for the casual safari goer. On safaris in Africa, India and Sri Lanka, I had also been disappointed at how little many local guide know about the behaviour of wild cats. This is not their fault; the knowledge tends to be buried in the more scientific publications. To address this knowledge gap when writing Wild Sri Lanka I introduced a chapter on the behaviour of leopards. Leopards like many of the species of wild cats are solitary animals. Much of what I wrote for that book and have adapted for this article holds true for many of the big cats that people go on safari to see. There are notable exceptions. Lions for example are social not solitary. However, other behavioural aspects such as scent marking, flehmen, defending territories etc., hold true for all cats.

This article also has a section on why Sri Lanka is so good for Leopard. Although it is specific to Sri Lanka it carries a general message to wildlife reserve managers all over the world. If you want to conserve an apex predator in good numbers, first address how you increase the population of its prey. Quite by chance, the Department of Wildlife Conservation in Sri Lanka has become a world leader in conserving and sustaining high wild population of a big cat.

Leopard Safaris – why Sri Lanka is so good
Yala National Park in Sri Lanka has now gained acceptance as the best place in the world to see and photograph leopards. This is particularly satisfying for me as I began the mantra that Yala is one of the best, if not the best place in the world to observe leopards. I had been on leopard safaris since the age of three when my Uncle Dodwell de Silva used to take me to Yala and Wilpattu to see leopards. But it was only in 2002 that I began to brand and market it as a mainstream tourism icon. Unfortunately it has suffered the law of unintended consequences with the leopard centric marketing building up to a level where the visitor experience can be spoilt by people behaving badly. But this is a solvable problem and I hope with education and better discipline, it will be resolved.

A main plank of my efforts to market the leopard was the work by the late Ravi Samarasinha, a medical doctor. When he was stationed at Hambantota, inspired by the work of the late Harith Perera he began to meticulously photograph and record the location of leopards in Block I of Yala. We would have meals together and thumb through his books which were a personnel file of each leopard in the park. He had marked each encounter with an individual leopard on a map with dates and times. Samarasinha was of the view that in certain parts of Block 1, the average density was as high as one leopard per square kilometer. In this measure, he included all individuals including cubs and sub-adults. Certain observations by me and that of other observers support the view that such a high density is plausible in certain prey-rich pockets. In April 2010, I observed 6 leopards within 600m. This is bettered by photographers who have had 6 leopards in the field of view at the same time at waterholes in the dry season where a carcass had drawn in leopards. However as leopards can be drawn to water and carcasses, this should not be confused with densities, although the presence of so many leopards close to each other is indicative of a high density. Andrew Kittle and Anjali Watson, two other researchers who were supported by Jetwing at the former Yala Safari Game Lodge believe the density of leopards is more likely to be one leopard per three square kilometers.

The actual number I suspect will lie somewhere between one leopard per one and three square kilometers. But whatever it is, leopard safaris have come a long way since I began to publicise it as a commercial product and raised eye brows in the tourism industry about whether there were enough leopards to show tourists.

This leads to the question as to why Yala (and Wilpattu) is so good for leopards. In 2002 there were a series of factors which had remained true for centuries and now there is an added factor; habituation. The original factors fall into two broad classes. The natural underlying density and secondly, the encounter rate.

The density of a carnivore will be correlated to the availability of its prey, water, denning sites, and lack of hunting by humans and predation from other hunters. Yala is a perfect habitat designed for carnivores because it is ironically a man-modified habitat which maximizes the population of its prey. The higher the prey the higher the number of predators. Spotted Deer is the preferred prey for leopards in Sri Lanka and Yala has an astonishingly high mass of protein on hooves per square kilometer. If you ever spend an hour at a waterhole in Yala during the dry season this will become obvious. Deer are abundant because Yala is former agricultural land which was farmed centuries ago and has subsequently reverted to thorn scrub forest. The forest cleared for farmland has resulted in grasslands. Furthermore, the park has a number of man-made lakes and waterholes. Given the abundance of foraging and water, the density of prey is very high. The recent focus on leopard safaris means that the park management also does more to maintain water in the waterholes. Management measures include de-silting waterholes, expanding them and even lining some of them with concrete bottoms to hold water. At the interventionist end of the management scale is the regular filling of waterholes with water brought in by bowsers. This will reduce the mortality of deer in the dry season resulting in an even better year round supply of food for leopards. Despite the many criticisms levelled at the Department of Wildlife Conservation, they have become a world leader in managing a park for leopards.

I have explained why there are so many leopards in Yala in terms of density. This is not the same thing as being able to see them or their encounter rate. There are three key reasons for seeing leopards easily in Yala. Firstly, in Sri Lanka it is the top terrestrial predator. To explain further, it is not at risk of being hunted by other animals other than crocodiles who will only take leopards opportunistically when they come to drink water. In India, they will be at risk from Tigers. In Africa they are at risk from Lions and Hyenas. This means in Sri Lanka they can be bold and lie about fairly fearlessly. Secondly, the thorn scrub terrain is open and provides better opportunities to see a leopard than if it was dense forest or tall grassland. Thirdly, and increasingly increasing in importance is habituation. As far as I can remember the leopards in Yala and Wilpattu were always used to vehicles. To be more specific there were always a few individuals who were more tolerant than others and provided a lot of the extended sightings whilst other individuals were shy.

Thanks to the work of Ravi Samarasinha, starting in 2002 I was able to thrust into the international media specific individuals such as JRMC1 and GMC5, using the coding he used for them. However, in the early years it was a case of one or a pair of cubs who would entertain the cameras. As leopards attain adulthood they become increasingly nocturnal. The intense leopard watching has now ushered a change. There is no doubt that with so many vehicles now targeting leopards, the cats are becoming more blasé about the company of vehicles. I use the term 3G leopards derived from a conversation with conservationist Ruskshan Jayewardene. He noted that for the first time we have a generation of leopards who are growing up with parents and grandparents who have been the focus of leopard safaris. They the third generation of 3G leopards are less likely to inherit a fear of visitors in vehicles. Before long there will be a 4G generation and so on.

I have been in leopard watching log jams in Yala where people have behaved more badly than if they were in a zoo. It has annoyed serious wildlife enthusiasts who would have liked to enjoy a sighting without having to hear others shout across and have conversations with occupants of other vehicles. But it has not disturbed the 3G Leopards who have continued to doze atop a rock. But as I said before, visitor discipline is needed. For those who prefer their leopards without crowds, consider having your safari organized by one of the specialist wildlife tour operators. They can arrange for safari vehicles to take you away from the main circuit travelled by general visitors. They will be happy to give you a longer game drive. But note that they are subject to the same opening and closing hours. Therefore a longer game drive means you stay later on the morning game drive or go in earlier for the evening game drive. The specialist wildlife tour operators also provide specialist naturalist guides. You may still have to take the mandatory park guide, but the good naturalist guides provided by the companies in Colombo speak good English and are good all-round naturalists.

Understanding the behaviour of leopards and other cats
Leopards are easy enough to see at times. But this section will help you to understand some of the behaviour you may see.

Age profiles: Generally the term cub is used to describe the age period from birth to about 18 months when they are totally dependent on the mother. From this age to about 2.5 to 3 years they will be described as sub-adults when they are beginning to fend for themselves and are acquiring a territory.

Eye sight: Contrary to what most people think, humans have higher visual acuity than leopards. However cats have a large number of light sensitive rods in their eyes which enable them to see in the dark, unlike us. Their eyes are six times more sensitive than ours although colour may play a limited role in their eyes. So although they can see in the dark, humans have sharper vision.
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Flehmen: **A grimace made by animals to draw in breath sharply and deeply. This breath together with the scents in the air is sampled in their Jacobson’s Organ which conveys a wealth of information which is not available to humans.

Jacobson’s Organ: Leopards in common with many mammals (but not humans) have an organ at the base of their brain called the Jacobson’s Organ. A duct on the upper jaw is connected to nerve centers on the brain to allow for sampling of the air to take place. By smelling the urine of another leopard they can probably sex and age it and even gauge the physical condition of it. Thus leopards can maintain territories by using a form of ‘chemical warfare’ and avoid physical contact which could lead to fatal injuries.

Nocturnal: Many carnivorous animals are nocturnal hunters. In Sri Lanka, leopards have become habituated in certain parks and young adults have been seen to hunt during the day. But as they become mature adults they switch to nocturnal hunting. This could be because hunting is very energy consuming and hunting at night in cooler temperatures is less energy intensive. Where they are at risk from people, most carnivores will prefer to hunt at night when disturbance is minimal. Studies on wild dogs in Africa have shown that the time needed to hunt goes up exponentially (not linearly as expected) when hunters are subject to disturbance.

Sawing: A Leopard’s contact call sounds like a saw cutting though wood. This is usually heard when leopards are making contact with each other. They may occasionally use it for intimidation. I have observed a leopard sawing and pawing at the base of a tree to panic a troop of Hanuman Langurs in the hope that one animal will misjudge a leap and fall to the ground.

Scent marking: Leopards have scent glands between the digits of their feet, on their face in the mystical areas and they also have an anal scent gland. Opinions differ as to whether a secretion from the anal glands is mixed into the urine spray. The scent glands on their feet are probably used when they scratch or scuffle the ground. This probably leaves a visual mark as well as a scent mark. They often rub their faces on favourite branches, etc and leave scent marks by doing so. They also rub against each other and thus scent marks each other.

Most often, the scent marking by leopards is done by spraying urine. They urine spray by pointing their penis backward and upwards. Marking the underside of the leaves may leave the scent more durable as it reduces the effect of being washed off by rain.

Scratching: Cats also lean up and scratch trees. Leopards don’t do this very often. Tigers are more likely to do this. The height and the extent to which an animal can gouge a trunk with its claws may be a signal to other leopards of the size and physical condition of the leopard making the marks.

Sexual dimorphism: This refers to the sexes being different in appearance, this could be a difference in size or colour patterns. In most cats this is a difference in size although with lions the males are also distinguished by having manes. By the age of 15 months a male leopard cub is the size of an adult female and at 18 months it can be larger than its mother. Many reports I receive of a courting pair are in fact of a mother and her male cub or a pair of cubs of different sexes. Even in the 21st century, this is poorly understood by many of the safari drivers and guides in the national parks.

Solitary vs. Social: Most cats are solitary animals. A male will hold a territory which will encompass that of a few females. The male has little physical contact with the female other than to mate and does nothing to help with the upbringing of the young. They will remain in contact though their scent marking. Lions are a notable exception amongst cats who have adopted a social strategy. A few pride males will guard access to the females. If they are overthrown by other males, the take-over males will often kill any cubs (infanticide) so that the females become ready to mate.

Territory sizes: In Yala National Park, the territory size of a female leopard could be as small as 4-6 square kilometers. A male's territory may be 4-5 times that and encompasses the territories of 4- 5 females. The small territory sizes in Yala are unusual and arise because of the high density of its preferred prey animal, the Spotted Deer. Female cubs when they grow up usually occupy a territory close to the mother. Males disperse far, which helps reduce in-breeding. Male mortality can be high as they compete with territory holders. I have seen a leopard sub-adult in Yala which had been killed by another leopard.

Credits
This article has been adapted and expanded from Wild Sri Lanka by John Beaufoy Publishing, written by Gehan de Silva Wijeyeratne.

These images are captured in Yala & Wilpattu National Parks in Sri Lanka.