Mortality records (1979–2011) shed light on threats to Asian Elephants Elephas maximus Linnaeus, 1758 (Mammalia: Proboscidea: Elephantidae) in Nilgiris, southern India
Main Article Content
Abstract
We compiled records of 291 elephant deaths over a 33-year period (1979–2011) from the Mudumalai Tiger Reserve and the reserved forests of Nilgiri North and South divisions of southern India from the databases of the Tamil Nadu Forest Department, the Wildlife Protection Society of India and the Nilgiri Wildlife and Environment Association. We tested the null hypothesis that the causes of elephant deaths would not differ with time, by gender and with level of protection. We classified records by gender and age: adults (≥15 years), sub adults (5–15 years), juveniles (>1–<5) and calves (≤ 1). We organised records over 3-decade periods. The database consisted of 209 adults (≥15 years), 27 sub adults (5–15 years), 33 juveniles (>1–<5) and 22 calves (≤ 1). MTR had the maximum records (148) followed by NND (138) and NSD (4). The median age of death was 20 years for adult males and 30 years for adult females. Mean survival time for adult males was 22.45 years, and 31.84 for females. Poaching was responsible for the majority of deaths (40%), particularly of male elephants (82%), and unknown causes (31%) for the majority of female deaths (66%). Human-caused deaths, which included poaching and some accidents, averaged 72% between 1979 and 2000 and decreased to 22% during 2001–2011. Deaths due to unknown causes and diseases increased from 28% in 1979-1989 to 69% in 2001–2011. Relative to estimated population size, deaths attributed to poaching was higher in NND (47%) than in MTR (34%). The causes of death differed by region. In conclusion, the elephant population in the Nilgiris is at risk and needs stringent protection; the mortality database should be systematised; forensic capabilities upgraded, and detection of carcasses improved.Â
ÂArticle Details
Authors own the copyright to the articles published in JoTT. This is indicated explicitly in each publication. The authors grant permission to the publisher Wildlife Information Liaison Development (WILD) Society to publish the article in the Journal of Threatened Taxa. The authors recognize WILD as the original publisher, and to sell hard copies of the Journal and article to any buyer. JoTT is registered under the Creative Commons Attribution 4.0 International License (CC BY), which allows authors to retain copyright ownership. Under this license the authors allow anyone to download, cite, use the data, modify, reprint, copy and distribute provided the authors and source of publication are credited through appropriate citations (e.g., Son et al. (2016). Bats (Mammalia: Chiroptera) of the southeastern Truong Son Mountains, Quang Ngai Province, Vietnam. Journal of Threatened Taxa 8(7): 8953–8969. https://doi.org/10.11609/jott.2785.8.7.8953-8969). Users of the data do not require specific permission from the authors or the publisher.
References
Armbruster, P., P. Fernando & R. Lande (1999). Time frames for population viability analysis of species with long generations: an example with Asian Elephants. Animal Conservation 2: 69–73.
Baskaran, N. (2013). An overview of Asian Elephants in the Western Ghats, southern India: implications for the conservation of Western Ghats ecology. Journal of Threatened Taxa 5(14): 4854–4870; http://dx.doi.org/10.11609/JoTT.o3634.4854-70
Baskaran, N., U. Anbarasan & G. Agoramoorthy (2012). India’s biodiversity hotspot under anthropogenic pressure: A case study of Nilgiri Biosphere Reserve. Journal for Nature Conservation 20: 56–61; http://dx.doi.org/10.1016/j.jnc.2011.08.004
Beck, C.A. & N.B. Barros (1991). The impact of debris on the Florida manatee. Marine Pollution Bulletin 22: 508–510; http://dx.doi.org/10.1016/0025-326X(91)90406-I
Burn, R.W., F.M. Underwood & J. Blanc (2011). Global trends and factors associated with the illegal killing of elephants: A hierarchical Bayesian analysis of carcass encounter data. PLoS ONE 6(9): e24165; http://dx.doi.org/10.1371/journal.pone.0024165
Choudhury, A., D.K.L. Choudhury, A.A. Desai, J.W. Duckworth, P.S. Easa, A.J.T. Johnsingh, P. Fernando, S. Hedges, M. Gunawardena, F. Kurt, U. Karanth, A. Lister, V. Menon, H. Riddle, A. Rübel & E.
Wikramanayake (2008). IUCN SSC Asian Elephant Specialist Group. (http://www.iucnredlist.org/details/7140/0, viewed 25 July 2013).
Clubb, R., M. Rowcliffe, P. Lee, K.U. Mar, C. Moss & G.J. Mason (2008). Compromised survivorship in zoo elephants. Science 322: 1649; http://dx.doi.org/10.1126/science.1164298
Daniel, J.C., A.A. Desai, N. Sivaganesan & S. Rameshkumar (1987). The Study of Some Endangered Species of Wildlife and Their Habitats - The Asian Elephant. Report of the Bombay Natural History, September, BNHS, Bombay.
Davidar, P., M. Arjunan, P.C. Mammen, J.P. Garrigues, J.P. Puyravaud & K. Roessingh (2007). Forest degradation in the Western Ghats biodiversity hotspot: resource collection, livelihood concerns and sustainability. Current Science 93: 1573–1578.
Davidar, P., S. Sahoo, P.C. Mammen, P. Acharya, J.P. Puyravaud, M. Arjunan, J.P. Garrigues & K. Roessingh (2010). Assessing the extent and causes of forest degradation in India: Where do we stand? Biological Conservation 143: 2937-2944; http://dx.doi.org/10.1016/j.biocon.2010.04.032
Davidar, E.R.C., P.R. Davidar, P. Davidar & J.P. Puyravaud (2012). Elephant, Elephas maximus Linnaeus (Proboscidea: Elephantidae) migration paths in the Nilgiris Hills, India in the late 1970s. Journal of Threatened Taxa 4(14): 3284–3293; http://dx.doi.org/10.11609/JoTT.o3008.3284-93
Desai, A.A. (1991). The home range of elephants and its implications for management of the Mudumalai Wildlife Sanctuary, Tamil Nadu. Journal of the Bombay Natural History Society 88: 145–156.
Desai, A.A. & N. Baskaran (1996). Impact of human activities on the ranging behavior of elephants in the Nilgiri Biosphere Reserve, south India. Journal of the Bombay Natural History Society 93: 559–569.
Jacobsen, J.K., L. Massey & F. Gulland (2010). Fatal ingestion of floating net debris by two Sperm Whales (Physeter macrocephalus). Marine Pollution Bulletin 60: 765–767; http://dx.doi.org/10.1016/j.marpolbul.2010.03.008
Kumar, V. & P. Dhar (2013). Foreign body impaction in a captive Sambar (Rusa unicolor). Veterinary World 6: 49–50; http://dx.doi.org/10.5455/vetworld.2013.49-50
Leimgruber, P., J.B. Gagnon, C. Wemmer, D.S. Kelly, M.A. Songer & E.R. Selig (2003). Fragmentation of Asia’s remaining wildlands: implications for Asian Elephant conservation. Animal Conservation 6: 347–359; http://dx.doi.org/10.1017/S1367943003003421
Lomolino, M.V. & R. Channell (1995). Splendid isolation: patterns of geographic range collapse in endangered mammals. Journal of Mammology 76: 335–347; http://dx.doi.org/10.2307/1382345
Moser, M.L. & D.S. Lee (1992). A fourteen-year survey of plastic ingestion by western North Atlantic seabirds. Colonial Waterbirds 15: 83–94.
Prasad, M.M. (2000). Where Does the Forest Begin? Economic and Political Weekly 4138–4140.
Remi-Adewunmi, B.D., E.O. Gyang & A.O. Osinowo (2004). Abattoir survey of foreign body rumen impaction small ruminants. Nigerian Veterinary Journal 25: 32–38; http://dx.doi.org/10.4314/nvj.v25i2.3472
Richards, N. (ed.) (2011). Carbofuran and Wildlife Poisoning: A Global Perspectives and Forensic Approaches. John Wiley & Sons Inc.
Silori, C.S. & B.K. Mishra (2001). Assessment of livestock grazing pressure in and around the elephant corridors in Mudumalai Wildlife Sanctuary, south India. Biodiversity and Conservation 10: 2181–2195; http://dx.doi.org/10.1023/A:101328591065
SPSS Inc. (2000). SYSTAT, Version 10. SPSS Inc., Chicago, IL.
Sukumar R. (1989). The Asian Elephant: Ecology and Management. Cambridge University Press.
Sukumar, R. & C. Santiapillai (1993). Asian Elephant in Sumatra; population and habitat viability analysis. Gajah 11: 59–63.
The Indian Forest Act (1927). http://envfor.nic.in/legis/forest/forest4.html (viewed 09 February 2015).