Sharon L. Gursky is Biological Anthropology Program Coordinator and Professor of Anthropology at Texas A&M University, USA. She is currently studying ultrasonic vocalizations in Philippine tarsiers, Tarsius syrichta. Upcoming research will focus on elucidating the function of the ultrasonic vocalization for this species.

• Chapter 1: Taxonomic HistoryChapter 2: Field Site and Data Collection MethodsChapter 3: Ecological and Social Factors Selecting for Gregariousness:Chapter 4: Ecological and Social Factors Selecting for GregariousnessChapter 5: Infant Care and the Cost of Infant Transport Chapter 6: The Cost of Nonmaternal Caretakers: Paternal and Subadult Infant CareChapter 7: Conservation Status of Spectral Tarsiers Chapter 8: Summary and Conclusions