A short report on research of an arid zone leopard population (Panthera pardus kotiya), Ruhuna (Yala) National Park, Sri Lanka. A. M Kittle*^ & A. Watson* Introduction The leopard (Panthera pardus kotiya) is the largest of four wild cat species recorded on the island of Sri Lanka. It is the islands only large cat species and its top predator. This population has evolved geographically separated from the mainland species (Panthera pardus fusca) and is now recognized as one of the nine subspecies of Panthera pardus currently extent in the world (Miththapala et al 1996; Uphrykina et al.2001). The following is a summary of some of the results of a 20-month long comprehensive field study conducted on a population on the south east coast of Sri Lanka. It is the first population of this subspecies to be studied intensely and forms the pilot study of long term ongoing research by the authors of P. p. kotiya in all extent habitats on the island. Study site and Methods The study site (6°16’-24’ N, 81°23’-31’ E) was a 127 km2 section of Ruhuna (Yala) National Park, Block I. For details refer to Kittle & Watson 2004. We traversed the existing 166 km unpaved road system within the study area daily primarily between approximately 05:30 and 11:30 and again between 15:30 and 22:00 to coincide with peak leopard activity. Not all roads were traveled every day, the route dependent upon such factors as recent activity. Individual identification of leopards was conducted using both facial and body spot pattern analysis (Miththapala et al 1989; Karanth 1994). First hand sightings, still and video image captures (of second hand sightings) and camera trap (TrailMaster 1550) images were utilized for this. Data was analyzed on the basis of capture-recapture models. Pug mark analysis, primarily for adult males who tend to have more individualized prints was intensively used as an additional identification tool. All sighting and pugmark locations were recorded on a Garmin E-trex summit GPS unit and transcribed onto a detailed grid map of the study site. Home range data was compiled and calculated using the minimum convex polygon method. A monthly census was conducted using Hirst’s (1969) road strip census method with a visibility index calculated over the seasons. Specific routes averaging 22 km were censused between 16:00 and 19:00 covering three previously determined sectors within the study site. Feacal samples were macroscopically analyzed to identify prey species consumed (hair, hooves, quills and bone remains were used). All signs- scrapes, spray- were measured and recorded. A canvas hide was erected at kills. Decay rates and rate of consumption of kills were monitored daily until fully consumed or until the leopard did not return to the kill. All dead prey species that we encountered that were not killed by a leopard were also monitored for decay rate and scavenging activity. Results and Discussion Population: The study population had a density (Table 1) rivaling areas in South Africa considered to be prime leopard habitat (Bailey 1993). Other international studies (Norton & Henley 1987; Bothma & Le Riche 1984; Hamilton 1976; Schaller 1972; Kostyria A.V. 2004 (unpublished data)) conducted in a variety of habitat types show lower densities than this population. At this point it appears that a combination of abundant prey and artificially maintained permanent water sources (Kittle & Watson unpublished data) and the lack of con-specific competition as well as the natural life history attributes (social structure, reproductive strategy (see below)) of the leopard allows for such density. Reproduction and Dispersal: There appears to be no birth season or peak for this population as recorded births (n = 17) were scattered across months. From the number of observed births, the reproductive rate of the study population appears healthy, however the cubs born during the study period appear to have a 45% chance of survival into full, reproductive adulthood (first year mortality estimated at 44.8% from 11 litters X 2.14 cubs/litter = 23.54 cubs). On average young leopards did not leave their natal ranges until they were ~24 months old. A number of the study individuals were not observed again after this time. Given enough space, these young animals have the ability to spread to adjacent areas even though pressure upon them from human settlements, inferior habitat and existing resident animals exists. Block 1 is the southern terminus of a much larger conglomeration of protected forest habitat which is assumed to be large enough to allow a percentage to disperse successfully. During the study there was evidence of one male dispersing into the southern buffer zone of the study site and south of his natal area. Another male observed (Fig.1) from the time he was a cub dispersed at 19 months (he was 28 months at date of last observation) and was in the process of attempting to establish territory 2-4 km north of his natal area. Spatial behaviour: The study population’s land tenure system is very similar to what is accepted as typical for wild leopard populations (Bailey 1993). The resident males occupy areas approximately three times larger than resident females (Table 2). The boundaries of resident male home ranges generally overlap the entire or partial home ranges of 4-6 resident females. Adult resident males within the study area exhibited a great deal of range overlap amongst themselves; however they also occupied “core” areas within their home ranges which they did not share with other adult males (Table 2). Sub-adult leopards shared their natal home range with their mothers. Adult resident males appeared very tolerant of sub-adults, although after approximately 2 years most sub-adults disappeared or were seen with less frequency in their natal areas. This could be associated with increased pressure to leave the area, exerted on the young animals by the residents. Occasionally injuries were observed that would be consistent with con-specific rivalry. Social behaviour: Leopards are essentially solitary animals. However, they live in a complex social system wherein there is constant non-verbal communication between individuals and not infrequent verbal communication. Consistent with previously observed behaviour, the leopards in our study area used an array of olfactory signals in order to communicate their whereabouts as well as advertise their reproductive state. Spraying urine and anal secretions onto particular shrubs and into scraped patches of earth (scent marking) (Fig.2) are the preferred methods . The resonant and distinctive ‘sawing’ call was the form of vocalization most frequently noted during our study. This call was also not infrequently heard in the vicinity of kills. A number of other calls were encountered during the study, associated with specific behaviours/interactions. These include 1) the short staccato half-saw contact calls between a mother and her cubs, 2) the soft mewing that combined with the retraction of the upper lip and appeared to indicate distress and 3) a characteristic growl of warning most frequently emitted at kills at the approach of wild boar (Sus scrofa). Female leopards were more social than males as they stayed, to varying degrees, with their cubs for up to 2 years. During this time they were also occasionally sought out by the resident male of the area. Females resumed their reproductive cycle immediately after the dispersal of cubs. This resulted in more frequent visits by the resident male. Three of the resident females become pregnant shortly after (or just prior) their 2 year old offspring had dispersed. Feeding ecology: We collected over 250 fecal samples during the study. These have provided insights into the feeding ecology of the leopards in Block I with regards to prey preferences and the wide-ranging nature of their diet. The preferred prey in the study areas was axis deer (Axis axis). This species is the most abundant prey source in the study area (Kittle & Watson 2002). Wild boar (Sus scrofa), sambhar (Cervus unicolor) and young buffalos (Bubalus bubalis) were the next choice of prey while evidence of porcupine (Hystrix indica), pangolin (Manis crassicaudata), mouse deer (Tragulus meminna), land monitor (Varanus cepedianus) and grey langur (Semnopithecus priam thersites) were also found. Selective scavenging was an important aspect of the feeding behaviour of the Block I leopards. 67% (n = 21) of naturally dead buffalo, wild boar and deer that were detected by leopards were scavenged. One of three dead elephants was also selectively scavenged, the feeding made easier by the post mortem incisions made by the Department of Wildlife Conservation (DWLC). General behaviour: Leopards in the study area infrequently hauled their kills into trees (11%, n = 63). We attribute this low percentage to the lack of direct competing carnivores in Ruhuna (Yala). It is possible that the lack of competition and the relative abundance of prey (Kittle & Watson 2002) allowed leopards within the study area to minimize their kill protection efforts. Leopards in the study area were not strictly nocturnal. While activity levels were highest during the hours of darkness, they were also active to varying degrees during the daytime and particularly in the crepuscular hours surrounding dawn and dusk (Fig 3). With the onset of night leopards with kills returned to them to feed, usually arriving around sunset. While most hunting activity appears to occur at night, kills made during the day were not uncommon. Summary In general the leopards inhabiting our study site within Block I of Ruhuna (Yala) National Park were similar in structure, diet range and social behaviour to populations encountered elsewhere in the world. The managed conditions of this arid zone ecosystem have allowed for a high population density as well as perhaps being partially responsible for the reduced incidences of stashing carcasses in trees. It is in fact interesting that leopard behaviour and societal structure are so in-keeping with the norm of the species in a wider context, as the Sri Lankan sub-species Panthera pardus kotiya is unique among leopards in that it has evolved in the absence of any large carnivore competition. Therefore it appears that the intrinsic life-history attributes of the species are forceful in determining population structures and functions across habitat types and circumstances. Evidence of this is the fact that the study area appears to have the capacity to hold more leopards if measured strictly by the prey base, water sources, potential den sites and lack of large carnivore competition (Kittle & Watson 2002). However, as it is not simply the carrying capacity of the ecosystem that is acting on the leopard population, but also internal mechanisms that seem to be responsible for determining such factors as home range size, resident sex ratio maintenance and reproductive activity, the equilibrium that has been achieved appears to be below the mathematically determined carrying capacity. The Leopard Project – aalanka@sltnet.lk The Wilderness & Wildlife Conservation Trust Sri Lanka. University of Guelph Department of Zoology Ont, Canada. References Bailey, T.M 1993. The African Leopard: The Ecology and Behavior of a Solitary Felid. Columbia University Press, New York. Bothma, J. duP. and E. A. N. Le riche. 1984. Aspects of the ecology and behaviour of the leopard (Panthera pardus) in the Kalahari Desert. Koedoe (supplement) 27: 259- 279. Hamilton, P.H. 1976. The movements of leopards in Tsavo National Park, Kenya, as determined by radio-tracking. M. Sc. thesis, University of Nairobi. Hirst, S.M. 1969. Road-strip Census Techniques for wild ungulates in African woodland. Journal of Wildlife Management. 33: 40-48 Karanth, K.U. 1994. Estimating Tiger Panthera tigris populations from camera-trap data using capture-recapture models. Biological Conservation 71: 333-338. Kittle, A.M. and A. Watson. 2004. Observations of a Rusty Spotted Cat population in an arid zone habitat. Cat News, Cat Specialist Group. London. No.40: 17-19. Kittle, A.M. and A. Watson. 2002. Report to the Department of Wildlife Conservation and Ministry of Environment and Natural Resources, Biodiversity Unit. Sri Lanka. Miththapala, S., J. Seidenstiker, and S.J. O’Brian. 1996 Phylogeographic subspecies recognition in leopards (Panthera pardus): molecular genetic variation. Conservation Biology 4:1115-1132 Miththapala, S., J. Seidenstiker, L.G. Phillips, S.B.U. Fernando and J.A. Smallwood. 1989. Identification of Individual Leopards (Panthera pardus kotiya) using spot pattern variation. Journal of Zoology, The Zoological Society of London, 218, 527-536. Norton, P. M., and S. R. Henley. 1987. Home range and movements of male leopards in the Cedarberg Wilderness Area, Cape Province. South African Journal of Wildlife Research 17: 41-48. Schaller, B.B. 1972. The Serengeti lion. University of Chicago Press, Chicago. Singh, L.A.K. 1999. Tracking Tigers: Guidelines for estimating wildtiger populations using the pugmark technique (revised edition). WWF Tiger Conservation programme, New Delhi. Uphyrkina O., Johnson W. E., Quigley, H., Miquelle, D, Marker, L., Bush, M and S.J.O’Brian. 2001. Phylogenetics, genome diversity and origin of modern leopard, Panthera pardus. Molecular Ecolgy 10, 2617-2633. Acknowledgments We would like to thank the following: Ministry of Environment and Natural Resources, Biodiversity Unit for Financial Support. Additional sponsors Arpico, Jetwing Research Initiative of the Jetwing Group of Companies and the Yala Safari Lodge, The Sri Lanka Wildlife Conservation Society (SLWCS), Mr & Mrs Watson and Mr. D.D.N Selvadurai Mr.Garmini Gamage and Mr. Ajith Silva (Director & Deputy Director, Biodiversity Unit), the Department of Wildlife Conservation, Mr. Kariyawasam, Mr. Herath, Mr. Ratnayake and Mr. Pathiratne. The field personnel and administrative staff at the Palatupana office – Mr.Mohamed, Mr. Abeykone, Mr. Jayaratne, Rangers Mr. Prasanna and the late Mr. Kumarasingha and the trackers who tirelessly worked with us. Saty Watson, Ravi Samarasingha, Soma, Manilal Gunatunga, Gehan De Silva Wijeyratne, Tina Dias, Saliya Dharmadasa, Rukshan Jayawardena, Namal Kamalgoda, Jehan Kumara, Thushara Kapurusingha, Gehan Rajapakse, Noel Rodrigo, Nanda Senanayake, Christopher Silva, Vajira Wijeygunwardena, Pershy Yogandranathan and all the other regulars to the park and the jeep drivers who contributed by way of information and photos.   «Back