Abstract: Sociality of wild animals involves a constant trade-off between fitness benefits and costs of living in groups, and this trade-off can be influenced by the social and ecological environment in which individuals live. Monica Bond will present research exploring socioecological factors underlying the social and spatial population structure and dynamics of a large tropical herbivore with a high fission-fusion social system, the giraffe (Giraffa camelopardalis). The Masai Giraffe Conservation Science project is jointly run by researchers from Penn State, the University of Zurich, and the Wild Nature Institute, and has collected a dataset of more than 3,000 identified individuals over 8 years in the coupled human-natural Tarangire Ecosystem of northern Tanzania. Using state-of-the-art mark-resight techniques and social network analyses, the research team (1) investigated natural and anthropogenic factors as mechanisms of giraffe social structure, space use, and vital rates; (2) quantified fitness consequences of social behaviors of adult female giraffes in relation to the influence of their physical environment; and (3) compared social versus spatial dispersal of subadult female and male giraffes.