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The leopard is the most widespread of all the big cats. The typical form came from Egypt but its present range extends from sub-Saharan Africa across the Arabian Peninsula into the Indian sub-continent and further eastwards to China, Korea, the Russian
Fareast, Peninsular Malaysia and Java. In Sri Lanka the leopard was once widely distributed across much of the island from sea level to over 2,000 m. More recently, a combination of forest conversion and poaching has reduced substantially, both the number and range of the leopard. Nevertheless, viable populations occur both within several protected areas as well in the remote forested areas in the north and east.
Ecology
The leopard is a highly adaptable felid. It inhabits both the semi-arid, thorn scrub of the lowlands and the dense montane cloud forest of the highlands. However, it is essentially a forest animal: even those adapted to semi-arid conditions appear to have a physiological need for shade during the heat of the day. Although in Sri Lanka it is the least nocturnal of all the felids, in places where it has learned to fear man, the leopard becomes much more cautious and nocturnal. It is usually solitary, unless accompanied by dependent young or during courtship and mating. In undisturbed areas, it spends considerable part of its daily activity on the ground, seeking refuge of the trees only at times. Rocky outcrops are often used as vantage points.
The leopard has excellent night vision, and hunts largely on sight. It is more an opportunistic predator than any other felid, and will attempt to kill any prey it comes across. As predators, leopards must spend a considerable amount of time locating and capturing prey. The classic hunt consists of stalk, chase and kill. Despite its relatively small body size, the leopard is still capable of taking large prey, and is extremely adaptable to changes in prey availability. In general, females with cubs are more successful in killing the prey that they encounter than males. Females also use their slightly smaller home ranges more effectively in capturing prey. Should the prey density become very low however, a female would range over a wider area, since her behaviour is usually more closely keyed to resources, given the responsibility of raising young. Leopards at times may drag their kill up into the branches of tall trees in order to avoid the unwelcome attention of other predators and scavengers such as jackals, wild boar or crocodiles. Leopards seem to prefer prey in the 20-70 kg size category, with an upper limit at about 225 kg, two or three times the weight of the cat itself
The leopard always attacks its large quadruped prey by seizing it by the throat with its teeth and strangling it while grasping it firmly round the neck and shoulders with its strong forelegs, and commence feeding on the soft parts of the belly first. The amount of meat eaten by an adult leopard may vary from 8 to 18 kg in 12 hours. Given that almost a quarter of the kill consists of inedible portions, a leopard may have to kill prey amounting to 487-584 kg per year to survive. Although its principal prey in Sri Lanka is the spotted deer (Axis axis), several other herbivores may function as buffer prey items. When the prey types available in an area are grouped according to their size, a clear preference for medium-sized herbivorous mammals emerges in leopard kills. Scats show the remains of wild boar (Sus scrofa), mouse deer (Moschiola meminna), porcupine (Hystrix indica), black-naped hare (Lepus nigricollis) and even water buffalo (Bubalus bubalis). Especially significant is the leopard's capacity to subsist on small prey such as rodents, snakes, game birds, even when "normal" prey is available. It can even feed on carrion. It is this catholicity of diet that enables the leopard to prey off a wide range of herbivore species and other food resources. Man-eating leopards are rare in Sri Lanka: the famous Punani man-eater was shot over its last human kill by R. Shelton Agar in 1924, after it had killed and devoured at least 12 people.
The main vocalization of the leopard is a rough, rasping sound similar to that of a saw cutting wood. Through these calls, leopards are able to maintain their spacing and also respond to members of the opposite sex during the breeding season. In addition, leopards also hiss and growl when angry, grunt when alarmed, and caterwaul when treed by dogs. Home range size in carnivores increases with the metabolic needs of the animals. The minimum estimates of the home range of the leopard in Sri Lanka vary from 4 to 10.5 km2. Females occupy territories that may overlap with those of other females slightly. But the much larger male territories overlap those of several females in an area. The boundaries of the territories are defended in fights and are marked throughout by urine sprayed onto logs, tree-trunks, and bushes in the course of the leopard’s extensive travels around its territory. However, a leopard usually covers a great part of its range every few days, and rarely stays in one spot for two nights in succession. While the male home ranges do not overlap, the adult females might share a part of their range with a male. Within their home ranges, the leopards scent-mark by squirting urine on trees and bushes. Leopards also make scrape marks on the ground, on trunks of trees and defecate in prominent places, to communicate their presence in the area. The density at which leopards occur varies with the availability of prey. In Block I of Ruhuna National Park, Sri Lanka, where prey is abundant, leopards occur at an average density of about 0.25 per km2.
Felids appear to be seasonally polyestrous in temperate regions and completely polyestrous in the tropics. Leopards reproduce when they are 2-3 years old. The onset of breeding may be associated with the rasping calls, which increase in frequency during estrous. Females are sexually receptive at 3-7 week intervals, and the period of receptivity lasts for a few days, during which mating is frequent. After a gestation period of about 98-105 days, on average 3 cubs are born blind and furred in a burrow, hollow log or in a rocky cave. They are weaned in three months. Leopard cubs are adapted for a "feast and famine" food regime from a very early age. Male cubs usually disperse from the natal area when they are about between 8 months and 2 years old, while female cubs remain within the mother’s territory and eventually take over a part or all of her territory. Average longevity in the wild could be about 10 years, although in captivity leopards may live up to 20 years.
Conservation
The number of predators in Sri Lanka is a measure of the island’s biological diversity and ecological richness. The existence of carnivores highlights the presence of a much larger ecological community, of which the leopard is at the top of the food chain. The leopard was once very numerous and widespread in Sri Lanka. Just how numerous it was could be appreciated from the numbers that were killed officially: between 1872 and 1899, a total of 8,473 animals were destroyed for which rewards were paid. In the Mannar District alone, 582 leopards were killed between 1854 and 1886. At the turn of the century, the number of leopards in the island was estimated at 1,660, when at least 50% of the land was under forest cover. Since then however, the forest cover has declined to less than 23%, while the human population has increased to over 19 million by 2000. Any assessment of leopard numbers is difficult, given the secretive nature of the felid and its capacity to exist in unlikely localities without betraying its presence. Today, perhaps between 400-600 leopards may survive in Sri Lanka. While it is impossible to be certain that this conservative estimate is correct, it is clear that the numbers of the leopard in Sri Lanka can now be measured in ‘hundreds’ whereas in the last century, it would have been estimated in ‘thousands’. The greatest threat to any wild felid comes from the increasing use of poison in agricultural areas. Given its propensity for scavenging, the leopard is more susceptible to taking poisoned meat. It is also widely poached for its skin, even within protected areas. Thus the leopard is subject to the vicissitudes of the illegal fur trade coupled with the acceleration of its habitat destruction. Therefore it may be among the most seriously endangered species of large mammals in Sri Lanka. Today, the leopard survives in a few small populations of unknown size. Yet not all small populations are ipso facto doomed. If habitat and other resources are available, and if the area is well protected, a species may increase rapidly. If several small, isolated populations persist, gene flow may possibly be maintained artificially by an occasional exchange of individuals. Conservation areas that support leopards in Sri Lanka must be of sufficient size to ensure at least the minimum viable populations could survive within their boundaries. Outside protected areas, the best opportunity for leopard conservation appears to lie in some form of multiple-use-pattern of forest development. The future for all wild cats in Sri Lanka is not likely to be rosy, if habitat loss continues unabated. The unnecessary extinction of any species represents a loss to human welfare. Reference
to the above material from:
©
Rukshan Jayewardene1, Iroshan Kulatunga2 and Charles Santiapillai3 (2003)
1
University of Maryland (USA)/University of Cambridge (UK) For the Leopard Trust
2
Dharmaraja College, Kandy, Sri Lanka
3
University of Peradeniya, Sri Lanka
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