Forest Elephant Group Dynamics, Social Interactions, and Population Monitoring

Forest elephants (Loxodonta cyclotis), the smallest and least studied of the three extant elephant species, predominately inhabit the Guinean and Congolian tropical forests from Guinea to the Democratic Republic of Congo. Known as ecosystem engineers, forest elephants create and maintain forest habitat, shape faunal communities, transport nutrients, and disperse seeds to distant areas. Despite their essential ecological role, very little is known about forest elephant social behavior. Living in social groups provides individuals with many benefits, including information about resources, protection from predators, and access to mates. For highly social species, like elephants, understanding social behavior is crucial to implementing sustainable conservation practices and mitigating the negative impacts of human development. To date, what is known about forest elephant social behavior originates from observations in baïs – mineral rich forest clearings. As a result, our understanding is limited by the short periods of time forest elephants spend in baïs, less than 2% of their time, and the small area relative to the rest of their home range and lifespan that we are able to observe. In this dissertation, I present research from the first project to attempt to understand elephant social interactions from throughout the range of habitats that forest elephants exploit on a daily basis, including dense, closed-canopy forest. I combine genetic and satellite technologies (GPS tracking and remote sensing) using novel computational methods to address: (1) factors that influence fluctuations in forest elephant group size; (2) forest elephant group age-sex composition and the factors influencing the probability of interactions between two elephants; and (3) improvements to forest elephant monitoring via line transect surveys for dung by creating an adaptive dung decay model. I conclude that: (1) group size is variable with forest elephants displaying a fission-fusion social system – a flexible social system in which individuals or sub-groups intermittently join other groups – across habitats in response to fruit availability and human disturbance; (2) interaction between individuals is influenced by social, but not environmental, factors and forest elephants spend more time in mixed sex groups than Asian or savanna elephants; and (3) estimating dung degradation via remotely sensed imagery is a feasible, cost-efficient alternative or supplement to in-situ dung degradation studies for non-invasive population surveys. This dissertation highlights the value of untangling the complex interplay between environmental, social, and anthropogenic drivers of species group composition and social behavior to inform conservation action., the results herein will be informative for monitoring forest elephant populations and promoting human-elephant coexistence through improved management of potential conflict areas.