Gap Analysis of Periyar - Agasthyamalai Landscape for Arboreal Mammal Conservation
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Gap analysis of Periyar - Agasthyamalai landscape for arboreal mammal conservation Final Technical Report 2013 Gap analysis of the Periyar – Agasthyamalai landscape for arboreal mammal conservation Final Technical Report 2013 Supported by Foundation for Ecological Research Advocacy and Learning (FERAL) 170/3, Tiruchittrambalam Road, Morttandi Village, Auroville P.O., Vanur Taluk. Villupuram District Tamil Nadu 605 101 India. http://www.feralindia.org Suggested Citation: Sushma H.S., Ram, S. and Vaidyanathan, S. 2013. Gap analysis of the Periyar Agasthyamalai landscape for arboreal mammal conservation. Final technical report, Foundation for Ecological Research Advocacy and Learning (FERAL). Table of Contents Acknowledgements ................................................................................................................ 1 Executive summary ................................................................................................................ 2 Introduction ............................................................................................................................ 4 Objectives .............................................................................................................................. 6 Study area............................................................................................................................... 7 Methods ............................................................................................................................... 13 Results and discussion .......................................................................................................... 18 Conclusions .......................................................................................................................... 53 References ............................................................................................................................ 55 Appendix 1. .......................................................................................................................... 62 Appendix 2 ........................................................................................................................... 64 Appendix 3. .......................................................................................................................... 66 Acknowledgements This work would not have been possible without the financial support from CEPF-ATREE Western Ghats Small Grants. We are indebted to them. We thank the Principal Chief Conservator of Forests (Wildlife) and Chief Wildlife Warden Shri V. Gopinathan, IFS, Kerala Forest Department for research permission (permission no. WL 10-4944/2011 dated 27/12/11) and for his constant support and encouragement during the course of this work. We thank Principal Chief Conservator of Forests (Wildlife) and Chief Wildlife Warden Shri Rakesh Vashisht, IFS, Tamilnadu Forest Department for granting research permission (permission no. WL5/36458/2011 dated 14/02/12) and for his support and encouragement. We thank the DFOs Ranni, Punalur, Thiruvananthapuram Forest Divisions and Wildlife Wardens of Shendurney Wildlife Sanctuary, Thiruvananthapuram Wildlife Division, Srivilliputhur grizzled giant squirrel Sanctuary and Kanyakumari Wildlife Sanctuary for providing us logistic support and for their encouragement during the study. We are indebted to Dr. H.N. Kumara, scientist, SACON, Coimbatore and Dr. M. Balasubramanian, scientist Periyar Foundation, Thekkady for sharing information on arboreal mammals. We would like to thank all the participants of the workshop for providing their valuable inputs. We thank Shubhankar Chakravarthy for helping us with field work, without him it would not have been possible to complete surveys in Ranni Forest Division, Neyyar and Kanyakumari WLS. We also thank M. Naveen, and Deepan Chackravarthy who were involved with field work during the initial stages of the project. Most importantly, we are indebted to Elango and Pandi, our field assistants without whose assistance we would not have been able to carry out field surveys. We are particularly indebted to Ms Shanthi and Mr Rajendran at FERAL for their help on the administrative front and ensuring smooth functioning of the project. The first author would like to thank Drs Meena Venkatraman and Karthik Vasudevan for their valuable inputs and constant encouragement throughout the project. 1 Executive summary Globally, the most significant threat to biodiversity is habitat loss caused by human activities. Establishing Protected Areas (PA) has often been a strategy to deal with loss in biodiversity. The Periyar – Agasthyamalai landscape in the southern Western Ghats is one of the key areas for biodiversity conservation. This landscape (5758 km2) with vast stretches of forests supports many endemic and endangered species. Though a large part (3054 km2) of the landscape is under Protected Area network, there is still a vast extent of biodiversity rich forests outside this network (2704 km2). Given the forest contiguity, this landscape is expected to support viable populations of endemic lion-tailed macaque (Macaca silenus) and Nilgiri langur (Semnopithecus johnii). In addition to these, other diurnal arboreal mammals that occur in the landscape are the bonnet macaque (Macaca radiata), tufted gray langur (Semnopithecus priam), grizzled giant squirrel (Ratufa macroura) and the Indian giant squirrel (Ratufa indica). It is therefore an important site for conservation of these taxa. In order to step up ongoing conservation efforts at a landscape level, we carried out gap analysis for a community of diurnal arboreal mammals that occupy a wide array of habitats in this landscape. The main aim of the study was to identify and prioritize sites outside the current PA network that are critical for conservation of these species, assess existing PAs for adequate representation of these taxa and finally to prepare a draft of site specific recommendations for arboreal mammals conservation in the landscape. We carried out a detailed review and collation of existing information on arboreal mammal occurrence and conducted field surveys in sites where information was poor. Gaps in information regarding arboreal mammal occurrence were identified and surveys were carried out in sites which lacked information on occurrence of arboreal mammals. Several sites in the landscape e.g. Ranni, Konni, Punalur, Thiruvananthapuram Forest Division, Neyyar and Peppara Wildlife Sanctuaries in Kerala and Srivilliputhur, Kanyakumari Wildlife Sanctuaries in Tamilnadu lacked recent information on occurrence of arboreal mammals. Information from secondary sources were combined with information obtained from field surveys and they were used to build species distribution modeling using a maximum likelihood estimation method. These distribution maps were then used in prioritizing sites for conservation using a tool called 'Zonation'. We used 'Additive benefit function' analysis which considers species 2 richness in a site rather than probability of a single species occurring while prioritizing. The result is a hierarchical ranking of the landscape based on probability of occurrence of all species in a site. Our results indicate that a large extent (~ 1265 km2) of important sites for arboreal mammals outside the existing network of PAs. In the Agasthyamalai landscape ~ 90% of the landscape has already been incorporated under the existing PA network. On the other hand, in the Periyar landscape, 2336 km2 of contiguous forests exist outside the current network of Protected Areas. These forests are high priority sites for conservation of arboreal mammals. For long term persistence of these species in the landscape, it is essential that these sites are protected. Based on the results of the study, a working draft of recommendations was prepared which was discussed and finalized during a consultative workshop with managers and scientists working in the landscape. Some key recommendations include: rationalizing boundaries of Shendurney Wildlife Sanctuary to incorporate crucial sites in Kolathupuzha range and Peppara Wildlife Sanctuary to include sites in Palode and Paruthipally ranges for conservation of arboreal mammals; a contiguous stretch of 572 km2 of high priority areas falling within Ranni, Achenkoil and Konni to be incorporated into Periyar Tiger Reserve or set aside for creation of a new PA; mitigation measures for linear barriers such as deploying canopy bridges at appropriate places to facilitate movement of arboreal mammals across the Shencottah gap, regulating traffic on roads passing through forested sites such as Angamoozhy to Vallakadavu road; habitat improvement and fostering connectivity through stream corridors in sites closer to the Shencottah gap such as in Punalur and Thenmala Forest Divisions; research recommendations such as establishing baseline population estimates and habitat assessment for long term monitoring. In Tamilnadu, key recommendations include: protection of grizzled giant squirrels outside the Srivilliputhur Wildlife Sanctuary boundary by fostering incentive based mechanism with the local farmers; dry forests of Srvilliputhur and Tirunelveli Forest Division remain vulnerable to habitat degradation due to fuel wood collection from adjoining human settlements and therefore alternative fuel resources need to be explored; private estates in the upper reaches of these two sites need to be acquired for long term conservation of these sites; in Kanyakumari WLS,