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 factorsBenefits from interacting with conspecificsConflict 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 advancedInhabit 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

High

Low

Fre

quen

cy o

f as

soci

atio

n

Bif

urca

tion

dist

ance

Low

High

Individuals

Mother-offspring units

Family groups

Bond groups(third-tier unit)

Fourth-tier units

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

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 cousin0.125

0.5

0.5Siblings

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

Gunda Rajesh

Nandini Shetty Krishna

Ranga, Althaf

Hansraj Gautam

Ashok Kumar

Mihir Kulkarni

Evangeline Arulmalar