RESPIRATORY DISEASE IN THE NORTH AMERICAN CAPTIVE ORANGUTAN POPULATION ____________________________________ A Thesis Presented to the Faculty of California State University, Fullerton ____________________________________ In Partial Fulfillment of the Requirements for the Degree Master of Arts in Evolutionary Anthropology ____________________________________ By Megan Kathryn Fox Thesis Committee Approval: Sara E. Johnson, Chair John Bock, Department of Evolutionary Anthropology John Patton, Department of Evolutionary Anthropology Fall, 2017 ABSTRACT All species within the genus Pongo are Critically Endangered; the Bornean orangutan (Pongo pymaeus), the Sumatran orangutan (Pongo abelli), and the recently classified species from Batang Toru (Pongo tapanuliensis). The North American Orangutan Species Survival Plan (SSP) and zoological institutions that house orangutans work to educate the public regarding the threats these species face and support various conservation and research projects that are working to promote their survival into the future. Unfortunately, there are a number of health challenges that face the captive orangutan population. Respiratory disease is the leading cause of death in North American captive orangutans between the ages of 8-40 years. Conditions under which respiratory disease occur are not well understood. This project aims to identify factors that influence the presence of respiratory disease in the North American captive orangutan population. A survey was disseminated to accredited North American zoological institutions housing orangutans to determine overall prevalence of disease, species and sex differences, as well as intrinsic and extrinsic environmental risk factors. Results show that respiratory disease affects 20.78% of this study population (n = 154) and male orangutans are nearly 2.4 times more likely to have respiratory disease than females. No significance is found at the species level for presence or absence of respiratory disease. Symptoms associated with diagnosis of disease are compiled with the goal of increasing early detection and treatment. ii TABLE OF CONTENTS ABSTRACT ................................................................................................................... ii LIST OF TABLES ......................................................................................................... vii LIST OF FIGURES ....................................................................................................... x ACKNOWLEDGMENTS ............................................................................................. xiii Chapter 1. STUDY OVERVEW ............................................................................................ 1 Overview of Respiratory Disease in Captive Orangutans .................................... 1 Overview of Chapters ........................................................................................... 4 2. ORANGUTAN OVERVIEW ............................................................................... 7 Orangutans Past and Present ................................................................................. 7 History of Past Populations ............................................................................ 7 Current Populations ....................................................................................... 8 Orangutans in the Wild ......................................................................................... 12 Wild Orangutan Overview ............................................................................. 12 Female Philopatry and Male Dispersal .......................................................... 14 Orangutan Sociality .............................................................................................. 15 Social Organization ........................................................................................ 15 Variation between Bornean and Sumatran Populations and Age/Sex Classes .......................................................................................... 17 3. FEMALE ORANGUTANS .................................................................................. 20 Female Behavior ................................................................................................... 20 Female Social Behavior ................................................................................. 20 Female Philopatry and Relatedness ............................................................... 21 Female Ranging Patterns and Home Ranges ................................................. 21 Female Reproduction ............................................................................................ 23 Female Associations during Fecundity, Mating Preferences, and Female Choice ............................................................................................ 23 Female Reproductive Parameters ......................................................................... 25 iii Concealed Ovulation, Age of First Parturition, Interbirth Intervals, and Signs of Pregnancy ..................................................................................... 25 Mother-Infant Relationships and Parental Investment .................................. 26 Male Avoidance and Infanticide .................................................................... 27 4. MALE ORANGUTANS....................................................................................... 32 Male Behavior....................................................................................................... 32 Bimaturism and Behavior .............................................................................. 32 Flanged Males and Unflanged Males ............................................................ 32 Male Bimaturism and Development ..................................................................... 34 Male Secondary Sexual Characteristics ......................................................... 34 Male Reproductive Tactics ................................................................................... 36 Forced Copulations, Copulatory Behavior, and Reproductive Success ........ 36 Male Dispersal and Vocalizations ........................................................................ 39 Dispersal and Ranging Patterns ..................................................................... 39 Vocalizations ................................................................................................. 39 5. ORANGUTAN ECOLOGY ................................................................................. 41 Introduction to Orangutan Ecology ...................................................................... 41 Influence of Environment on Orangutan Behavior and Sociality ......................... 42 Geographic Variations between Populations ........................................................ 44 Species and Sub-Species ................................................................................ 44 Variation in Environment and Food Availability .......................................... 44 Variation in Morphology ............................................................................... 45 Variation in Life-Histories ............................................................................. 46 Variation in Sociality ..................................................................................... 46 Culture and Social Learning ................................................................................. 47 Orangutan Culture .......................................................................................... 47 Social Learning .............................................................................................. 48 Vocalizations and Communication ....................................................................... 50 Gestures ......................................................................................................... 50 Orangutan Vocalizations ................................................................................ 51 Long Calls ...................................................................................................... 52 6. ORANGUTAN CONSERVATION ..................................................................... 55 Conservation Overview ........................................................................................ 55 Influences on Conservation .................................................................................. 57 Orangutans and Geographic Variation .......................................................... 57 Logging and Orangutans ................................................................................ 57 Illegal Hunting ............................................................................................... 60 Palm Oil and Oil-Palm Plantations ................................................................ 61 Vulnerability of Female Orangutans .............................................................. 62 Conservation Efforts ...................................................................................... 62 iv 7. ORANGUTANS IN CAPTIVE ENVIRONMENTS IN-SITU AND EX-SITU . 64 Rehabilitant Orangutans/Numbers ........................................................................ 64 The Association of Zoos and Aquariums (AZA).................................................. 65 The Orangutan Species Survival Plan (SSP) .......................................................