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 Benefits from interacting with conspecifics Conflict from conspecifics
Degrees of Sociality
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
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).
African savannah elephants ooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo Wittemyer et al. 2005
Fission-Fusion Societies Fluid society
Genetic Relatedness Between Females Dung samples obtained upon observed defecation and DNA extracted and individuals genotyped at 14 nuclear microsatellite loci. Sujata Kardile
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. Siblings 0.25 First cousin Siblings Genetic Relatedness
Predation Resource availability Dominance Relationships High quality vs Low quality Clumped vs Dispersed Abundant vs Scarce (female reproductive success limited) Female transfer between groups Female-bonded groups
Predation Resource availability Dominance Relationships High quality vs Low quality Clumped vs Dispersed Female transfer between groups Female-bonded groups Scramble (egalitarian society) Contest (linear hierarchy)
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. Dominance Interactions
Acknowledgments: DST Ramanujan Fellowship, CSIR, National Geographic Society, JNCASR for funds State Forest Department of Karnataka for research permits, support Arjun Ghosh Deepika Prasad Keerthipriya GundaRajesh Nandini ShettyKrishna Ranga, Althaf Hansraj Gautam Ashok Kumar Mihir Kulkarni Evangeline Arulmalar