Yala National park
Yala National Park is located within Sri Lanka’s south-eastern arid zone, and is part of the 1,518 km2 Yala Group of National Reserves. Block I is the most accessible of these, and by far the most intensely visited, protected area in the country. Its 141 km² is mostly composed of woody scrub <5m in canopy height; interspersed with taller monsoon forest. Tall, climax forest with thin under-story, characterizes the northern riparian zone whereas dense, often thorny scrub, is the dominant forest type throughout the remainder of this coastal Block. Palu (Manilkara hexandra) and Weera (Drypetes sepiera) are the two most abundant canopy species, whereas Kumbuk (Terminalia arjuna) is commonly found along rivers. Open plains <1/2 km² in area, characterized by various grass and sedge species occur around, both seasonal and permanent waterholes.
This Park has a high degree of avifaunal and mammalian biodiversity. Home to over 140 bird species and a seasonal stopover for over a hundred more, Yala is a birdwatcher’s paradise. Particularly impressive are the array of water-birds and raptors. The former group includes Lesser Flamingoes (Phoenicopterus minor), White Ibis (Threskiornis melanocephalus), Lesser Adjutant Stork (Leptoptilos javanicus) and Spoonbills (Platalea leucorodia). Raptors include such sharp-eyed hunters as the Crested Serpent Eagle (Spilornis cheela speliogaster), Crested Hawk Eagle (Spizaetus cirrhataus) and the largest of the lot, the White Bellied Sea Eagle (Haliaetus leucogaster). Charismatic mammals also abound. Prominent among them are several herds of Asian elephants (Elephas maximus). The Sri Lankan leopard(Panthera pardus kotiya) is the island’s largest cat and an endemic, endangered sub-species. Block I has one of the highest densities of leopards recorded in the world with ~25 adult individuals residing here, no doubt a result of the large prey base, particularly axis deer (Axis axis), that thrive here due to the artificially enhanced water sources. The leopards of Yala block 1 are highly habituated making them less elusive. Sloth bears do well here too, thanks to abundant termites as well as the Palu trees which draw these shaggy forest denizens into their branches to gorge on its sweet, yellow fruits in May, a sight well worth seeing in Yala.
Yala National Park was once the site of an extensive civilization, the Rohana /Ruhuna Kingdom which lasted from 2 BC – 1000 AD. This advanced society used hydraulic management practices to collect and maintain rain water in this exceedingly dry habitat. As a result, dozens of artificial reservoirs (tanks), some maintained by park authorities, form perennial and annual water holes within the Block and serve to increase the water available for wildlife, in a naturally arid habitat. Numerous ruins and caves are found within rocky outcrops that rise up to 250m. These outcrops are quartzofeldspathic gneiss, erosion remnants, and are dominant features in otherwise flat terrain. Rock waterholes (“kemas”) within these outcrops are important sources of freshwater during the dry season. The Menik River separates Block I from Blocks II and III in the north and several seasonal streams flow through the park.
Temperatures here average 25º – 28ºC with a maximum of 37º and annual rainfall is less than 1000mm spread unevenly throughout the year. The dry season lasts from mid-May to mid-October with the wet season, which results from convectional rains and the northeast monsoon, runs from mid-October to end-January. An intermediate season characterized by occasional inter-monsoonal rains spans February to mid-May.
Written by: Anjali Watson & Andrew Kittle
Principal Researchers/ Founding Trustees
The Leopard Project
The Wilderness & Wildlife Conservation Trust