Fishing and Rusty Spotted
in Sri Lanka
Research Proposal: Distribution and Ecology of the Fishing Cats and Rusty Spotted Cats in Suburban Habitats of Sri Lanka
Background and Justification
As ‘urban sprawl’ inexorably continues to eat away at natural habitat, town planners are beginning to realize the need for setting aside natural habitats as ‘green areas’ for aesthetic reasons and also for practical considerations such as for flood control, recreation, and even biodiversity conservation (Goode 1989, McNeely 2001). Whereas land reclamation for town expansion and development around the larger cities of Sri Lanka continues apace, there are opportunities to set aside patches of marshes, forests, and mangroves even within the cities that can harbor populations of wildlife species.
Even now, small patches of forests and other natural habitat include species such as fruit bats, civets, mongooses, lorises, purple-faced leaf monkeys, fishing cats, spot-billed pelicans, blue coot, and jacanas, among others (Philips 1984).These patches are mostly ad hoc remnants, rather than ‘green areas’ set- aside by design. But if town planners can infuse conservation planning into their plans, green refugia can be more effective for biodiversity conservation and for conserving ecological functions.
As with conservation planning in natural habitats and habitat landscapes, the use of focal species (see Lambeck 1997) can be of value in planning these urban green areas. For them to be effective for conservation planning the focal species should have: wide ranging habitat requirements so they act as umbrellas for overall biodiversity; charismatic appeal for use as flagship species; and ideally should be habitat specialists.
In Sri Lanka, the fishing cat (Prionailurus viverrinus) and the rusty spotted cat (Prionailurus rubiginosa) can be used as focal species for planning urban green areas. Both species have charismatic appeal and are listed in the CITES Appendix II.
The fishing cat is a habitat specialist, inhabiting riparian habitats, swamps, and wetlands. Because these are critical ecosystems for preserving watershed and drainage functions and are among the first to be reclaimed or converted during urbanization the fishing cat is a suitable focal species for planning and highlighting the conservation of these habitats.
The rusty spotted cat is the smallest member of the cat family and is thought to be a habitat generalist, but little is known of its tolerance threshold for disturbance. It is infrequently encountered close to settlements, but this may be partly due to its secretive, nocturnal habits, and partly because when seen it may be mistaken for a domestic cat.
Museum records show that the rusty spotted cat had occurred in the suburbs of Colombo about 30 to 50 years ago, although no recent substantiated records exist. However confirmed observations from suburbs of mid-sized towns (e.g., Tissamaharama, Dambulla, etc.) indicate that these cats could survive in and around populated areas. If the presence of the rusty spotted cat can be ascertained and confirmed in and around the suburbs of Colombo, this small predator can be used as a flagship species for conserving patches of natural habitat in urban planning.
Therefore, this study seeks to survey urban and suburban habitats to confirm the presence and ascertain the distribution of the fishing cat and rusty spotted cat, and study their ranging patterns, behavior, and habitat requirements in suburban and urban environments. The techniques used (camera-traps) will also provide information on the presence of other meso-carnivores.
We will then develop a conservation plan for these species in urban and suburban environments that can be integrated into future city and town development plans. The study will also compare the ecology and behavior of both species with animals living in more natural conditions (proposed by other researchers in Sri Lanka).
The study will first focus in Colombo and its suburbs (first-tier study sites), including Nawala, Maharagama, Sri Jayawardenepura, Attidiya, Boralesgamuwa, and Moratuwa.
These areas used to contain lowland rain forests, marshlands, and wetlands. But during the past 2-3 decades, most of the natural habitat has been rapidly cleared for housing, as part of the development and expansion plan for Greater Colombo Area. However, numerous patches of forests, marshes, and other wetlands still remain within the matrix of development and human habitatation. The study area also contains two protected areas, the Attidiya and Sri Jayawardenepura sanctuary.
If surveys in the first-tier areas indicate that the two species (both or either) are absent, the survey area will be extended further afield from Colombo and suburbs to second-tier study sites that include Panadura to the south and Muthurajawela to the north.
If the two (both or either) species are not found in Panadura and Muthurajawela, we will conduct the study in Tissamaharama, a mid-sized town in the south, or in Dambulla in the north-central province (third-tier study sites).
This progressive selection of study areas will help to assess
a threshold of disturbance for presence of the fishing cats
and rusty-spotted cats.
A camera trapping program will be conducted to determine the distribution of fishing cats and rusty spotted cats. We will initially set out camera-traps in the first tier sites for 4-6 months. If the initial trapping does not indicate the presence of both species, the traps will be shifted to the second and third-tier sites.
Ten camera traps will be rotated in different habitat types; i.e, forest, scrub, wetlands, marshes, riparian, plantation, etc). Habitat patches will be mapped using 1:10,000 scale land use maps or aerial photographs, available from the Survey Department of Sri Lanka.
The level of anthropogenic disturbance will be classified using a categorical classification of the density of houses and other buildings within a 500 m ‘buffer zone’ around the habitat patch to determine disturbance thresholds for presence of fishing cats and for rusty spotted cats.
The habitat use and distribution information will be used in a GIS to model a conservation landscape (core areas, connectivity for dispersal, etc.) that can be used in urban planning using the fishing cat and rusty spotted cat as focal species. This plan will be used to integrate ‘green areas’ within the landscape matrix during development.
We will also conduct an awareness campaign through local magazine and newspaper articles, and presentations at various venues to raise the profile of fishing cats and rusty-spotted cats (and other meso-mammals such as otters, civets and birds) to flagship status for urban planning and conservation.
The project is being conducted by Ms. Suchitra Balagalle as partial fulfillment of requirements toward a M.Phil./Ph.D. from the Open University of Sri Lanka.
The project is supervised by
It is funded by the Smithsonian’s National Zoological
Park and Friends of the National Zoo.