Abstract:
Socioecological theory is a broad framework that attempts to explain the variation in
sociality amongst animals in terms of responses to resource-risk distributions (for example,
Crook and Gartlan 1966, Alexander 1974, Wrangham 1980, Terborgh and Janson 1986).
The ecological model of female social relationships (EMFSR, Koenig et al. 2013), which is
part of socioecological theory, posits that predation and food characteristics shape female
social organisation by making dispersal risky and determining the strength of scramble and
contest competition within and between groups (Wrangham 1980, van Schaik 1989, Isbell
1991, Wrangham et al. 1993, Isbell and van Vuren 1996, Isbell and Young 2002, Sterck et
al. 1997). Assessments of the abundance and distribution of resources, feeding competition,
and social relationships between individuals are required in order to test predictions from
the ecological model of female social relationships. A vast majority of the studies on
socioecology have been carried out on primates (for example, Chapman et al. 1995, Koenig
and Borries 2006, Snaith and Chapman 2007, Chancellor and Isbell 2009, Grueter et al.
2016, Teichroeb and Sicotte 2018, apart from the references mentioned above) and studies
of the EMFSR on other taxa are required (Clutton-Brock and Janson 2012). In this context, I
examined the relationship between food resources and within- and between-group contests
in a non-primate species, the Asian elephant (Elephas maximus), feeding primarily on grass,
traditionally thought of as a low-quality resource, in Nagarahole National Park and Tiger
Reserve, southern India.
This thesis is divided into two parts: 1) assessment of methods to estimate forage abundance
for Asian elephants, and 2) investigation of the influence of ecological variation on contest
competition within and between groups of female Asian elephants, and the social and
foraging consequences of dominance interactions. Since it is important to measure resource
abundance when examining the EMFSR but resource abundance is also difficult to directly
measure for elephants and has rarely been done before, the first two data chapters deal with
issues related to such measurements.
