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Social Organization in Female Asian Elephants T.N.C. Vidya Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore. Which is the odd one out?. Behaviour in Social Animals. Interaction between conspecifics in social animals Ecological factors
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Social Organization in Female Asian ElephantsT.N.C. Vidya Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore
Behaviour in Social Animals • Interaction between conspecifics in social animals • Ecological factors • Benefits from interacting with conspecifics • Conflict from conspecifics
Fission-Fusion Societies • Group sizes and compositions may vary but groups are not just random collections of individuals
Why Elephants? • Socially advanced • Inhabit ecologically diverse habitats
Study Area • Nagarahole, Bandipur National Parks, Karnataka: high elephant density, relatively good visibility
Individuals Identified • Calf: >0-1 yrs • Juvenile: >1-5 yrs • Subadult: >5-15 yrs • Adults: >15 yrs >5000 sightings
Low High Fourth-tier units Bifurcation distance Frequency of association Bond groups (third-tier unit) Family groups Mother-offspring units High Low Individuals Social Organization in Female Elephants • Qualitative family groups, joint family groups, clans(Mc Kay 1973, Kurt 1974, Sukumar 1989, Baskaran et al. 1995). • Association between individuals of “family” groups in Sri Lanka: 18-29% (Fernando and Lande 2000). • Association between individuals of family groups in Kenya: 70-90% (Moss 1988, Archie et al. 2005, Wittemyer et al. 2009).
Fission-Fusion Societies • Fluid society
Genetic Relatedness Between Females Sujata Kardile Dung samples obtained upon observed defecation and DNA extracted and individuals genotyped at 14 nuclear microsatellite loci.
Siblings 0.5 0.5 0.25 0.125 Siblings First cousin Genetic Relatedness • R of parent-offspring = 0.5, full siblings = 0.5 on average. • R of half sibs, parents’ siblings = 0.25 on average. • R of two randomly picked individuals in a population • with no inbreeding = ~zero.
Female transfer between groups Female-bonded groups Dominance Relationships • Predation • Resource availability Clumped vs Dispersed Abundant vs Scarce (female reproductive success limited) High quality vs Low quality
Female transfer between groups Female-bonded groups Dominance Relationships • Predation • Resource availability Clumped vs Dispersed High quality vs Low quality Contest (linear hierarchy) Scramble (egalitarian society)
Dominance Interactions • Dominance behaviours: chase, charge, displace, supplant, push, shove, lash out with trunk, kick. • Subordinate behaviours: cower, walk backwards, look backwards and walk, walk/run away from aggressor.
Acknowledgments: • DST Ramanujan Fellowship, CSIR, National Geographic Society, JNCASR for funds • State Forest Department of Karnataka for research permits, support Nandini Shetty Keerthipriya Arjun Ghosh Krishna Ranga, Althaf Hansraj Gautam Ashok Kumar Mihir Kulkarni Evangeline Arulmalar Deepika Prasad Gunda Rajesh