Population densities and conservation assessment of three threatened agamid species in Horton Plains National Park, Sri Lanka
DOI:
https://doi.org/10.22120/jwb.2020.118316.1115Keywords:
Cloud Forests, Lizard smuggling, Conservation, Agamidae, Distance methodAbstract
Horton Plains National Park is home for three endemic and threatened agamid species in Sri Lanka; Ceratophora stoddartii, Cophotis ceylanica and Calotes nigrilabris. This study was conducted to estimate the population densities of these lizard species within HPNP in 2016 and 2017. Line transect surveys were carried out following the “Distance” method to obtain population counts. A total of 288 transects were surveyed in two different time periods of each year; Dry months and Wet months. The program “Distance 7.1” was used for density calculations. Highest population density was recorded for Ce. stoddartii in the wet months of 2016 and 2017 (32.91 ind/ha, n=77; 26.70 ind/ha, n=66). However, Ce. stoddartii density was relatively lower in the dry months of both years (2016: 19.79 ind/ha, n=58; 2017: 17.18 ind/ha, n=55). Lowest population density was recorded for Ca. nigrilabris in the wet season of 2017 (7.80 ind/ha, n=38). The population density of Co. ceylanica did not show much fluctuation throughout all four sampling periods was relatively lower when compared with other species. These results indicate that more conservation focus is required to protect these agamids that have low and declining populations when compared to past literature available. They are also facing the threat of illegal smuggling.
References
Needs to Tackle Smuggling of Nationally Protected Species. Munich, Germany: Pro Wildlife, pp. 1-32.
Amarasinghe A.A.T., Tiedemann F., Karunarathna D.M.S.S. 2011. Ca. nigrilabris Peters 1860: A threatened highland agamid lizard in Sri Lanka. Amphibian & Reptile conservation5(2):33-43.
Auliya M., Altherr S., Ariano-Sanchez D., Baard E.H., Brown C., Brown R.M., Cantu J.C., Gentile G., Gildenhuys P., Henningheim E., Hintzmann J. 2016. Trade in live reptiles, its impact on wild populations, and the role of the European market. Biological Conservation 204 (Part A):103-119.
Bahir M.M., Surasinghe T.D. 2005. A conservation assessment of the Sri Lankan Agamidae (Reptilia: Sauria). The Raffles Bulletin of Zoology 12:407-412.
Bambaradeniya C.N. 2006. The Fauna of Sri Lanka: Status of Taxonomy, Research, and Conservation. Colombo, Sri Lanka: IUCN, pp. xiii, 308.
[BDS, MoENR]. Biodiversity Secretariat, Ministry of Mahaweli Development and Environment. 2009. Sri Lanka's Fourth National Report to the Convention on Biological Diversity. Colombo, Sri Lanka: Ministry of Mahaweli Development and Environment, pp. 13-16
Bossuyt F., Meegaskumbura M., Beenaerts N., Gower D.J., Pethiyagoda R., Roelants K., Mannaert A., Wilkinson M., Bahir M.M., Manamendra-Arachchi K., Ng P.K. 2004. Local endemism within the Western Ghats-Sri Lanka biodiversity hotspot. Science 306(5695):479-481.
Buckland S.T., Anderson D.R., Burnham K.P., Laake, J.L. 1993. Distance Sampling: Estimating Abundance of Biological Populations. London, UK: Chapman and Hall, pp. xii + 446.
Buckland S.T., Anderson D.R., Burnham K.P., Laake J.L., Borchers D.L., Thomas L. 2001. Introduction to Distance Sampling: Estimating Abundance of Biological Populations. New York, NY: Oxford University Press, pp. xv + 448.
Burnham K.P., Anderson D.R. 2002. Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach. New York, NY: Springer, pp. 49-97.
Chandrasiri S.P., Dharmarathne W.D.S.C., Lakmal S., Mahaulpatha W.A.D. 2015. Distribution of the Jungle Crow (Corvus levaillantii Lesson, 1831) and Their Potential Threats to Biodiversity in Horton Plains National Park, Sri Lanka. WILDLANKA5(2):073-077.
De Silva A. 2007. The Diversity of Horton Plains. Colombo, Sri Lnaka: Vijitha Yapa, pp. xvi + 373.
[DWC] Department of Wildlife Conservation. 2007. Biodiversity Baseline Survey: Horton Plains National Park. Consultancy Services Report prepared by Green, M.J.B. (ed.), De Alwis, S.M.D.A.U., Dayawansa, P.N., How, R., Singhakumara, B.M.P.,Weerakoon, D. and Wijesinghe, M.R. ARD Inc in association with Infotech IDEAS and GREENTECH Consultants. Sri Lanka Protected Areas Management and Wildlife Conservation Project (PAM&WCP/CONSULT/02/BDBS). Colombo, Sri Lanka: Department of Wildlife Conservation, Ministry of Environment and Natural Resources, pp. 1-28.
Erdelen W. 1988. Population dynamics and dispersal in three species of agamid lizards in Sri Lanka: Calotes calotes, C. versicolor and C. nigrilabris. Journal of Herpetology22(1):42-52.
Erdelen W.R. 2012. Conservation of biodiversity in a hotspot: Sri Lanka's amphibians and reptiles. Amphibian and Reptile Conservation 5(2):33-51.
Fernando G.W.A.R. 2008. Causes of forest dieback in montane forests in Sri Lanka. Economic Review 34:38-40.
Gunatilleke C.V.S., Gunatilleke I.A.U.N. 1986. Horton Plains: some aspects of its vegetation and ecology. Sri Lanka Wildl 3(4):9-11.
Hettiarachchi K., Daniel S. 2011. Spiriting out endemic species. The Sunday Times online. http://www.sundaytimes.lk/110710/Plus/plus_02.html. Downloaded on 27 February 2019.
Hettige P. 2011. Action against smuggling of reptiles. The island, online. http://www.island.lk/index.php?page_cat=article-details&page=article-details&code _title=23361. Downloaded in Feb. 2019.
Jayasekara E.G.D.P., Mahaulpatha W.A.D. 2018a. Behavior Associated with Habitat Utilization of Rhino Horned Lizard (Ceratophora stoddartii)(Sauria: Agamidae) in Montane Cloud Forests of Sri Lanka. Paper presented at: Towards Sustainable and Greener Future. Proceedings of the 22nd International Forestry and Environment Symposium. Waskaduwa, Sri Lanka.
Jayasekara E.G.D.P., Mahaulpatha W.A.D. 2018b. Rhino Horned Lizard Synchronizes its Breeding with the Life Cycles of Understory Plants in Montane Habitats of Horton Plains National Park. Paper presented at: Conservation-reef to ridge. Proceedings of the 6th Wildlanka International Symposium. Colombo, Sri Lanka.
Jayasekara E.G.D.P., Mahaulpatha W.A.D., De Silva A. 2018a. Habitat utilization of endangered rhino horned lizard (Ceratophora stoddartii)(Sauria: Agamidae) in the Horton Plains National Park, Sri Lanka. Journal of Entomology and Zoology Studies 6(4):1544-1549
Jayasekara E.G.D.P., Prabhath M.C., Mahaulpatha W.A.D. 2018b. Implications of invasive plant U. europaeus eradication programs on the grassland population of Ca. nigrilabris (Black-cheeked lizard) within HPNP. Paper presented at: Conservation-reef to ridge. Proceedings of the 6th Wildlanka International Symposium. Colombo, Sri Lanka.
Jayasekara E.G.D.P., Prabhath M.C., Mahaulpatha W.A.D. 2017. Behavior Associated with Habitat Utilization of Endangered Black-Cheek Lizard (Ca. nigrilabris) in the Grasslands of Horton Plains National Park in Sri Lanka. Paper presented at: Resource Management for Sustainable Service Delivery. Proceedings of the 22nd International Forestry and Environment Symposium. Waskaduwa, Sri Lanka.
Jenkins R.K., Brady L.D., Huston K., Kauffmann J.L., Rabearivony J., Raveloson G., Rowcliffe J.M., 1999. The population status of chameleons within Ranomafana National Park, Madagascar, and recommendations for future monitoring. Oryx 33(1):37-45.
Karsten K., Andriamandimbiarisoa L., Fox S., Raxworthy C. 2009. Population densities and conservation assessments for three species of chameleons in the Toliara region of south-western Madagascar. Amphibia-Reptilia 30(3):341-350.
Karunarathna D.M.S.S., Pradeep W.A.A.D.G.P., Peabotuwage P.I.K., De Silva M.C. 2011. First report on the ovipositional behaviour of Calotes nigrilabris Peters, 1860 (Reptilia: Sauria: Agamidae) from the Central massif of Sri Lanka. Russian Journal of Herpetology 18(2):111-118.
Karunarathna D.M.S.S., Amarasinghe A.A.T. 2008. An observation of the Jungle Crow (Aves: Corvidae) feeding on Ceylon Pygmy Lizards, Co. ceylanica (Reptilia: Agamidae) at Horton Plains NP in Sri Lanka. Sauria 30(4):59.
Manamendra-Arachchi K., Liyanage S. 1994. Conservation and distribution of the agamid lizards of Sri Lanka with illustrations of the extant species. Journal of South Asian Natural History 1(1):77-96.
Ministry of Environment (MOE). 2012. The National Red List 2012 of Sri Lanka; Conservation Status of the Fauna and Flora. Colombo, Sri Lanka: Ministry of Environment, pp 476.
Ministry of Mahaweli Development and Environment (MoMD&E). 2016. National Biodiversity Strategic Action Plan2016-2022. Colombo, Sri Lanka: Ministry of Mahaweli Development and Environment, pp. 1-274.
Myers N., Mittermeier R.A., Mittermeier C.G., Da Fonseca G.A., Kent J. 2000. Biodiversity hotspots for conservation priorities. Nature 403(6772):853.
Pethiyagoda R., Manamendra-Arachchi K. 1998. A revision of the endemic Sri Lankan agamid lizard genus Ceratophora Gray, 1835, with the description of two new species. Journal of South Asian Natural History 3:1-50.
Pethiyagoda R., Editor. 2012. Horton Plains: Sri Lanka's cloud-forest national park.Colombo, Sri Lanka: Wildlife Heritage Trust, pp.8-311.
Rao M.S., Rajabai B.S. 1972. Ecological aspects of the agamid lizards Sitana ponticeriana and Calotes nemoricola in India. Herpetologica 28(3):285-289.
Somaweera R., Somaweera N. 2009. Lizards of Sri Lanka: A Color Guide with Field Keys. Frankfurt, Germany: Edition Chimaira, pp. 11-288.
Thambyahpillay G. 1958. Rainfall fluctuations in Ceylon. Ceylon Geography 12:51-74.
Venugopal P.D. 2010. Population density estimates of agamid lizards in human-modified habitats of the Western Ghats, India. The Herpetological Journal 20(2):69-76.
Western D. 1974. The distribution, density and biomass density of lizards in a semi–arid environment of northern Kenya. African Journal of Ecology 12(1):49-6.
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