Completed Research Projects
The Giant Panda Management as a Model for the Malayan Tiger and Bornean Orang Utan Management in Malaysia: Rohana Jani, PhD (University of Malaya), Noor Hashida Hashim, PhD (University of Malaya), Mohd. Tajuddin Abdullah, PhD (University Malaysia Terengganu) and Dennis Ten Choon Yung (University of Malaya/PERHILITAN). The Giant Panda has been placed under the Endangered red list status since 1990.Its status has been down listed from Endangered to Vulnerable in 2016. The conservation works on the Giant Panda is indeed a successful conservation effort. While both IUCN Red List of Threatened Species status for the Malayan Tiger and Bornean Orang Utan have been elevated from Endangered to Critically Endangered in 2015 and 2014. Currently, the Giant Panda conservation model is proven as the successful wildlife conservation model; an in-depth adaption is needed to enable such model to be applied to other threatened species to ensure the model benefited to the targeted species. We seek to understand the Giant Panda conservation management and the possibility that the captive Giant Panda conservation management model may contribute to the conservation management of Malayan Tiger and Bornean Orang Utan. The survey exercise will be distributed to animal captive facilities. The outcome of the study is potentially contributed to the country zoo management and captive wildlife management.
A survey of the prevalence and perceived efficacy of biofloors in great ape exhibits within AZA zoos: Jill Moyse, Curator of Primates, Lincoln Park Zoo. This research project will survey AZA institutions that house great apes to investigate the type of biofloor, if any, the animals have access to throughout the day and overnight. The survey will look at the prevalence of bio floors and the decisions made to provide bio floors from a management perspective. By comparing the attitudes and experiences of institutions that have biofloors to those that do not, we hope to elucidate what the motivations are for institutions to install them as well as what the barriers are to including biofloors in the design of new buildings or the refurbishment of existing exhibits. It is expected that cost and concerns over hygiene will represent common barriers, but we also anticipate that responses from intuitions that have biofloors in their exhibit will dispel such concerns.
A search for chemical signals in orang-utans: Male orangutan cheek pads are frequently hypothesised to have arisen through sexual selection, influenced by female preference or by male-male competition. However, their potential role in attracting females is not yet fully understood – nor is their potential role in suppressing development in unflanged males. In this preliminary study, Dr Graham L Banes, Professor Tom E Goodwin (Hendrix College) and Melanie Bond (National Zoo, retired) are using use solid phase dynamic extraction (SPDE) gas chromatography mass spectrometry (GC-MS) to identify volatile organic compounds that may emanate from orang-utan cheek pads. The research was featured on the PBS documentary, “Sex in the Wild: Orangutans”.
Variation in Vocal Repertoires of Wild and Captive Orangutans: Although most research on great ape vocalizations has been on chimpanzees, recent field research has produced a catalogue of a wide variety of orangutan vocalizations. Geographic variation in orangutan vocalizations has been identified both within call type and in the presence of certain vocalizations among wild populations. This study aims to catalogue vocal recordings collected across AZA zoo-housed orangutan collections and compare these to those previously documented in the wild. We are especially interested in the context of vocalizations, in novel vocalizations, and in the extent to which keepers can identify the meaning of the vocalizations they hear and record. Please click here for project description and information on participation; click here for contact information.
Respiratory Disease in the North American Captive Orangutan Population: Megan K. Fox of the Los Angeles Zoo and Botanical Gardens and Graduate Student, Evolutionary Anthropology at California State University, Fullerton. This project aims to identify some of the factors that influence the presence of respiratory disease in the North American captive orangutan population. Understanding if there are species differences in the prevalence of disease between the Sumatran and Bornean orangutan, between the sexes, between certain age classes, and between individuals at various developmental stages will provide valuable information and assist in the management of these species. This project also aims to identify other factors that may influence the onset of disease, such as weight, body condition, family history, rearing history, stress events, and environmental factors. Additionally, this project will provide information on the types of symptoms most commonly experienced that will also contribute to the possible early treatment and diagnoses of respiratory disease in captive orangutans. Identifying the risk factors involved will greatly enhance the ability for zoological institutions to act preemptively to treat disease which can ultimately assist in the overall care, management, and survivability of the individuals involved and hence the population as a whole. Contact Megan Fox here.
Insulin Resistance in Old World Primates: Dr. Elena Less of the Cleveland Metroparks Zoo is studying biomarkers of insulin resistance over time in several primate species, orangutans being the representative for apes. Dr. Less’s goal is to determine the effect of increasing age/time spent in captivity on insulin, glucose, cholesterol and triglycerides in banked serum samples from orangutans, Hamadryas baboons, mandrills, ring-tailed lemurs, and red ruffed lemurs. Click here for project description and information on participation; click here for contact information. PENDING ANALYSIS
Important Diseases of Rehabilitant Orangutans: Clinical Aspects of Epidemiology, Diagnosis and Treatment: The Central Kalimantan Orangutan Reintroduction Project of the Borneo Orangutan Survival Foundation at Nyaru Menteng (BOS-NM) holds the largest population of captive orangutans in the world, and associated health and veterinary records over a number of years. Analysis of the data contained within the clinic records, along with some investigative procedures, could fill in a number of knowledge-gaps, and contribute to the health and welfare of captive orangutans not only within BOS-NM, but across the world. Rosalie Dench is working to summarize retrospectively the incidence of orangutan diseases at BOS-NM and establish normal reference ranges for body weight and blood results for the population, which can act as a baseline for analyses, as well as evaluate current diagnostic methods in more detail for several diseases of significance. Click here for more detail on this project; click here for contact information. Work on TB testing, Air Sacculitis Risk Factors and normal ranges for orangutan bodyweight and haematology parameters has already been completed; please contact Rosalie Dench for further information.
Thyroid histology in orangutans with non‐congenital thyroid dysfunction, led by Dr. Sandra M. McLachlan of Cedars‐Sinai Medical Center in Los Angeles. This project investigated thyroid dysfunction in great apes by examining thyroid hormone levels and TSH in all nonhuman great ape genera including adults, adolescents, and infants, and establishing a thyroid hormone and TSH database in orangutans, gorillas, chimpanzees, and bonobos (447 individuals). The most striking differences found between these 4 great ape genera were greatly reduced FT4 and FT3 levels in orangutans and gorillas, and elevated TSH levels in gorillas, compared with chimpanzees and bonobos. In addition, autoantibodies to Tg and TPO were detectable in only 2.6% of adult great apes, significantly lower than the approximately 10% in humans. No great apes with thyroid autoantibodies exhibited thyroid dysfunction and neither thyroid autoantibodies nor thyroid lymphocytic infiltration were present in hypothyroid great apes. The researchers also concluded that hypothyroidism in the closest surviving human relatives may involve dietary components including goitrogens but is unrelated to thyroid autoimmunity. Click here to read the Endocrinology article detailing this work.
Cataloging Blood Types for SSP Populations of Great Apes, led by Kathryn Gamble and Jill Moyse, Lincoln Park Zoo. In humans and domestic mammals, blood typing plays an important role in providing excellent medical care in critical care situations. It has been repeatedly demonstrated that humans and great apes have conserved identities within the standard blood typing categories of A-B-O and D(Rh factor). Development of simple table-top laboratory techniques to identify these most basic of blood groups in human patients may be applied to similar benefit in the great ape species. Click here to read the Zoo Biology article detailing this work.
Jaw Gape in Primates, William Hylander, Duke Lemur Center. This project is part of a broad-based comparative study on feeding adaptations in anthropoid primates. There may be important morphological differences in terms of jaw mechanics between orangutans from Borneo as compared to those from Sumatra. If these supposed differences prove to be significant, this will indicate important morphological differences in terms of orangutan jaw-muscle architecture. This in turn is likely related to differences in feeding ecology. This project is now complete and data are being prepared for publication; results will be posted here when available.
Factors influencing male orang-utan reproductive success, Dr. Graham L. Banes, Max Planck Institute for Evolutionary Anthropology. Male orang-utans exhibit one of two physical forms: dominant males develop large 'cheek pads' on their faces, while socially subordinate males do not. The purpose of these ornaments has long been poorly understood. Though cheek pads are hypothesised to make dominant males more attractive to females, thus resulting in greater reproductive success, males without them are also known to have fathered offspring in the wild and in zoos — so why develop cheek pads if you can father offspring without them? A team led by Dr Graham L Banes of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, performed paternity testing of orang-utans at Camp Leakey in Tanjung Puting National Park, Indonesia, to see if the dominant male — Kusasi — was more reproductively successful than his rivals. Not only did Kusasi father almost all of the offspring born during his period of dominance, other males typically only achieved conceptions at the beginning and end of Kusasi's reign, when the dominance hierarchy was potentially unstable. The authors concluded that male bimaturism is likely to be an evolutionarily stable strategy, in which non-cheek-padded males simply bide their time until periods of rank instability. The methods for genetic analyses used in this research, which was published in September 2015 in the journal Behavioral Ecology and Sociobiology, were developed using faecal samples from the Los Angeles Zoo and Botanical Gardens, CA, St Paul's Como Zoo and Conservatory, MN, and Henry Vilas Zoo in Madison, WI. The study was featured by The Washington Post, Discovery News and The Daily Mail, and profiled on Serious Science. Preliminary findings were originally presented at the 9th Annual Orangutan SSP Husbandry Workshop at the Los Angeles Zoo and Botanical Gardens in August 2013.
Cytokine Production and Urinary Excretion in the Orangutan: Drs. Lyle Moldawer and Erin Vogel are investigating the hypothesis that a high degree of endotoxin-responsiveness and cytokine production is shared by orangutans and humans. Their study seeks (1) to determine cross-reactivity among orangutan cytokines and human immunoassay reagents, (2) to determine ex vivo cytokine production to bacterial endotoxin by whole blood obtained from orangutans, and (3) to measure hemopexin and other acute phase reactant proteins that bind endotoxin (LBP, BPI) in the plasma of orangutan. Click here for project description and information on participation; click here for contact information.
A retrospective study of cardiovascular disease in captive orangutans (Pongo sp.): This study, conducted by Drs. Amanda Marino and Lauren Howard, will provide a systematic review of the current cases of cardiovascular disease diagnosed in captive orangutans pre-mortem. This project will provide an overview of the unique attributes of orangutan physiology and how it may affect cardiac function, as well as how heart disease in orangutans differs from other great apes. Additionally, this paper will act as a source of information on the clinical signs of disease, risk factors of disease, and the current thoughts on how to manage cardiac disease in orangutans. This paper will advance our knowledge of cardiovascular disease and improve our ability to diagnose and treat captive orangutans. Please click here for project details, information on participation, and contact information.
Retrospective Classification and Management Assessment of Canine Fractures in Captive Managed Populations of Great Apes: Jill Moyse, Curator of Primates, Lincoln Park Zoo. At this time, it is unknown how many individual great apes in the captive population have broken, fractured and or cracked canine teeth. As several approaches for treatment or repair are possible, it is not known which of these injuries correlate best with the available management options. Long-term effects of no treatment are not predictable. The retrospective project will survey the captive managed great ape population to assess the occurrence of injuries and what treatment was provided to the animal. Zoo veterinarians will be surveyed to document any great apes in their collection that have any incidents of breakage, cracked or fracture of the canine teeth in the last 10 years. We anticipate majority to full participation from the SSP institutions that house great apes and will be able to compile an inventory of all animals that currently have canine fractures, breaks or cracks, the treatment they received and if any common risk factors are associated with the canine fractures. With this information, it is anticipated that prospective guidance of treatment options can be provided to institutions, veterinarians and the great ape SSP when animals present a fracture, break or cracked canine.
Orangutan fecal microbiome analysis: Stephanie McCain, DVM, Dipl ACZM (Birmingham Zoo), Richard Sim, DVM, Dipl ACZM (Oregon Zoo), and Casey Morrow, PhD (University of Alabama, Birmingham). An inordinate number of zoo housed orangutans have either chronic constipation or chronic diarrhea, with an underlying cause rarely identified. (Nancy Lung, personnal comm.) Many zoos must manage one or both of these conditions, regardless of diet fed, illustrating the need to have a better understanding of orangutan GI health. The goal of this study is to understand how the gut microbe community structure correlates with and can influence the health and behavior of zoo-housed orangutans. In order to accomplish this goal, we plan to perform microbiome analysis on fecal samples from all individual orangutans housed in the United States and evaluate these results against diet, fecal consistency, and pedigree. (Approved January 2020) PENDING ANLYSIS
The influence of plant secondary metabolites on diet selection, nutrition, and health of wild Bornean Orangutans: William Aguado (PhD Candidate, Rutgers University) and Erin Vogel, PhD (Rutgers University & Tuanan Orangutan Research Project). Plant secondary metabolites (PSMs)—the toxic, unpalatable, or otherwise harmful chemical compounds that are produced in plants—are thought to play an important role in determining what primates can and do eat. Orangutans presumably encounter such compounds in their biodiverse environments, yet the role PSMs play in their nutritional ecology is poorly understood. This study examines how a common class of PSM called tannins, inhibits nutrient digestion and influences foraging behavior of Bornean orangutans at the site of Tuanan, in Central Kalimantan, Indonesia. We use behavioral observation, nutritional analysis of plant foods, and urinary biomarkers of nutritional stress to answer these questions. Gaining a better understanding of the chemical predictors of orangutan diet selection can help shed light on their ecology and evolution, contribute to our nutritional prescriptions for these apes in captivity, and help to identify key resources that support wild orangutan populations.
Humor and teasing in great apes: Isabelle Laumer, PhD (Department of Anthropology, UCLA), Prof. Erica Cartmill (Department of Anthropology, UCLA). This study explores the forms and functions of teasing in zoo-living great apes, with a particular focus on playful teasing. Recent developmental studies suggest that non-verbal “playful teasing” is already visible in human infants in the first year of life. The occurrence of playful teasing in preverbal infants suggests that language is not a prerequisite for this behavior and, thus, that it might be present in our closest living relatives. We aim to gather information about the prevalence and types of teasing in zoo-living apes through a questionnaire for ape keepers sent to selected North American and European zoos. The purpose of this study is to systematically assess and identify different forms of teasing behaviors, in which apes try to provoke a social reaction from others. These interactions might resemble games, teasing, harassment, or surprising each other. Furthermore, we hope to better understand which animals (e.g. age classes) typically perform provocative behavior and to whom it is directed. We are also interested in how apes respond to teasing from others. Developing a more complete understanding of the dynamics of positive and negative teasing behaviors will contribute to zoos’ goals of better assessing and managing the complex social dynamics of zoo-housed primates and the findings of this study will make important contributions to comparative psychology and evolutionary biology. NPR Clip
Determination of normal reference intervals for thyroid hormone serum concentrations in orangutans (Pongo sp.): Melissa Fayette, DVM (Indianapolis Zoo), Anneke Moresco, DVM, PhD (Reproductive Health Surveillance Program), Emily Vincent, DVM (The Ohio State University), Brian Petroff, DVM, PhD (Michigan State University), and Dalen Agnew (Michigan State University). Thyroid disease has been reported anecdotally in several orangutans within the SSP population; however, accurate diagnosis of these conditions is hindered by a paucity of published reference intervals for thyroid hormone serum concentrations in this species. Thyroid hormones play a critical role in regulation of growth, metabolism, and reproduction. Excess or deficiency in thyroid hormones may lead to the development of potentially life-threatening conditions such as hypertension, cardiovascular disease, and diabetes and can also result in infertility. Thus, timely detection and treatment of thyroid dysfunction is essential given its potential impact on overall health and breeding success of this critically endangered species. The goal of this study is to establish baseline reference intervals for thyroxine (T4), free-thyroxine (FT4), free triiodothyronine (T3) and thyroid stimulating hormone (TSH) in healthy orangutans using commercially available chemiluminescence immunoassays validated specifically for use in this species and to determine the influence of sex and age on thyroid hormone serum concentrations.
Investigating the Composition of the Milk of Apes: Dr. Mike Power PhD, Mike Maslanka and Erin Stromberg, Smithsonian National Zoo. This is a continuation of ongoing research. The objective is to obtain longitudinal milk samples from apes (bonobos, chimpanzees, gorillas, orangutans, and gibbons), from shortly after birth until the female is no longer lactating, in order to further characterize the nutritional content of ape milk, continue investigating the milk microbiota of non-human primates, and learn more about the potential role of bioactive molecules in mother’s milk to regulate offspring physiology and metabolism (among other questions). Additional milk samples from females whose milk has not previously been collected are important to document the extent to which there are species-specific patterns and the extent of variation between females. To date, samples have been obtained from 3 orangutans and 7 lowland gorillas. We aim to receive samples from 10-12 individuals from each ape species in order to be able to fully characterize variation between females. Results of this work are shared widely for the benefit of zoos worldwide. Samples are available for collaborative research projects.
Development of a database of fetal ultrasound measurements for the creation of orangutan-specific (Pongo spp.) growth curves and determination of parturition dates: Current data is lacking in species specific fetal growth curves and gestation lengths for orangutans. Dr. Brittany Rizzo, along with Connie Warner, Dr. Joe Smith, and Dr. Ric Berlinski, is compiling existing fetal ultrasound and birth date information as well as gathering future information in the hopes of creating more accurate and species-specific fetal growth curves for orangutans. Data of this nature can benefit institutions via improved planning for their training and social structure changes. Additionally, in cases of animals that have had previous difficult births or emergency cesarean sections, accurate determination of gestational age for scheduling future cesarean sections can reduce the risk of complications for both the dam and the infant. Please click here for project description and information on participation; click here for contact information.
A survey of the prevalence and perceived efficacy of biofloors in great ape exhibits within AZA zoos: Jill Moyse, Curator of Primates, Lincoln Park Zoo. This research project will survey AZA institutions that house great apes to investigate the type of biofloor, if any, the animals have access to throughout the day and overnight. The survey will look at the prevalence of bio floors and the decisions made to provide bio floors from a management perspective. By comparing the attitudes and experiences of institutions that have biofloors to those that do not, we hope to elucidate what the motivations are for institutions to install them as well as what the barriers are to including biofloors in the design of new buildings or the refurbishment of existing exhibits. It is expected that cost and concerns over hygiene will represent common barriers, but we also anticipate that responses from intuitions that have biofloors in their exhibit will dispel such concerns.
A search for chemical signals in orang-utans: Male orangutan cheek pads are frequently hypothesised to have arisen through sexual selection, influenced by female preference or by male-male competition. However, their potential role in attracting females is not yet fully understood – nor is their potential role in suppressing development in unflanged males. In this preliminary study, Dr Graham L Banes, Professor Tom E Goodwin (Hendrix College) and Melanie Bond (National Zoo, retired) are using use solid phase dynamic extraction (SPDE) gas chromatography mass spectrometry (GC-MS) to identify volatile organic compounds that may emanate from orang-utan cheek pads. The research was featured on the PBS documentary, “Sex in the Wild: Orangutans”.
Variation in Vocal Repertoires of Wild and Captive Orangutans: Although most research on great ape vocalizations has been on chimpanzees, recent field research has produced a catalogue of a wide variety of orangutan vocalizations. Geographic variation in orangutan vocalizations has been identified both within call type and in the presence of certain vocalizations among wild populations. This study aims to catalogue vocal recordings collected across AZA zoo-housed orangutan collections and compare these to those previously documented in the wild. We are especially interested in the context of vocalizations, in novel vocalizations, and in the extent to which keepers can identify the meaning of the vocalizations they hear and record. Please click here for project description and information on participation; click here for contact information.
Respiratory Disease in the North American Captive Orangutan Population: Megan K. Fox of the Los Angeles Zoo and Botanical Gardens and Graduate Student, Evolutionary Anthropology at California State University, Fullerton. This project aims to identify some of the factors that influence the presence of respiratory disease in the North American captive orangutan population. Understanding if there are species differences in the prevalence of disease between the Sumatran and Bornean orangutan, between the sexes, between certain age classes, and between individuals at various developmental stages will provide valuable information and assist in the management of these species. This project also aims to identify other factors that may influence the onset of disease, such as weight, body condition, family history, rearing history, stress events, and environmental factors. Additionally, this project will provide information on the types of symptoms most commonly experienced that will also contribute to the possible early treatment and diagnoses of respiratory disease in captive orangutans. Identifying the risk factors involved will greatly enhance the ability for zoological institutions to act preemptively to treat disease which can ultimately assist in the overall care, management, and survivability of the individuals involved and hence the population as a whole. Contact Megan Fox here.
Insulin Resistance in Old World Primates: Dr. Elena Less of the Cleveland Metroparks Zoo is studying biomarkers of insulin resistance over time in several primate species, orangutans being the representative for apes. Dr. Less’s goal is to determine the effect of increasing age/time spent in captivity on insulin, glucose, cholesterol and triglycerides in banked serum samples from orangutans, Hamadryas baboons, mandrills, ring-tailed lemurs, and red ruffed lemurs. Click here for project description and information on participation; click here for contact information. PENDING ANALYSIS
Important Diseases of Rehabilitant Orangutans: Clinical Aspects of Epidemiology, Diagnosis and Treatment: The Central Kalimantan Orangutan Reintroduction Project of the Borneo Orangutan Survival Foundation at Nyaru Menteng (BOS-NM) holds the largest population of captive orangutans in the world, and associated health and veterinary records over a number of years. Analysis of the data contained within the clinic records, along with some investigative procedures, could fill in a number of knowledge-gaps, and contribute to the health and welfare of captive orangutans not only within BOS-NM, but across the world. Rosalie Dench is working to summarize retrospectively the incidence of orangutan diseases at BOS-NM and establish normal reference ranges for body weight and blood results for the population, which can act as a baseline for analyses, as well as evaluate current diagnostic methods in more detail for several diseases of significance. Click here for more detail on this project; click here for contact information. Work on TB testing, Air Sacculitis Risk Factors and normal ranges for orangutan bodyweight and haematology parameters has already been completed; please contact Rosalie Dench for further information.
Thyroid histology in orangutans with non‐congenital thyroid dysfunction, led by Dr. Sandra M. McLachlan of Cedars‐Sinai Medical Center in Los Angeles. This project investigated thyroid dysfunction in great apes by examining thyroid hormone levels and TSH in all nonhuman great ape genera including adults, adolescents, and infants, and establishing a thyroid hormone and TSH database in orangutans, gorillas, chimpanzees, and bonobos (447 individuals). The most striking differences found between these 4 great ape genera were greatly reduced FT4 and FT3 levels in orangutans and gorillas, and elevated TSH levels in gorillas, compared with chimpanzees and bonobos. In addition, autoantibodies to Tg and TPO were detectable in only 2.6% of adult great apes, significantly lower than the approximately 10% in humans. No great apes with thyroid autoantibodies exhibited thyroid dysfunction and neither thyroid autoantibodies nor thyroid lymphocytic infiltration were present in hypothyroid great apes. The researchers also concluded that hypothyroidism in the closest surviving human relatives may involve dietary components including goitrogens but is unrelated to thyroid autoimmunity. Click here to read the Endocrinology article detailing this work.
Cataloging Blood Types for SSP Populations of Great Apes, led by Kathryn Gamble and Jill Moyse, Lincoln Park Zoo. In humans and domestic mammals, blood typing plays an important role in providing excellent medical care in critical care situations. It has been repeatedly demonstrated that humans and great apes have conserved identities within the standard blood typing categories of A-B-O and D(Rh factor). Development of simple table-top laboratory techniques to identify these most basic of blood groups in human patients may be applied to similar benefit in the great ape species. Click here to read the Zoo Biology article detailing this work.
Jaw Gape in Primates, William Hylander, Duke Lemur Center. This project is part of a broad-based comparative study on feeding adaptations in anthropoid primates. There may be important morphological differences in terms of jaw mechanics between orangutans from Borneo as compared to those from Sumatra. If these supposed differences prove to be significant, this will indicate important morphological differences in terms of orangutan jaw-muscle architecture. This in turn is likely related to differences in feeding ecology. This project is now complete and data are being prepared for publication; results will be posted here when available.
Factors influencing male orang-utan reproductive success, Dr. Graham L. Banes, Max Planck Institute for Evolutionary Anthropology. Male orang-utans exhibit one of two physical forms: dominant males develop large 'cheek pads' on their faces, while socially subordinate males do not. The purpose of these ornaments has long been poorly understood. Though cheek pads are hypothesised to make dominant males more attractive to females, thus resulting in greater reproductive success, males without them are also known to have fathered offspring in the wild and in zoos — so why develop cheek pads if you can father offspring without them? A team led by Dr Graham L Banes of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, performed paternity testing of orang-utans at Camp Leakey in Tanjung Puting National Park, Indonesia, to see if the dominant male — Kusasi — was more reproductively successful than his rivals. Not only did Kusasi father almost all of the offspring born during his period of dominance, other males typically only achieved conceptions at the beginning and end of Kusasi's reign, when the dominance hierarchy was potentially unstable. The authors concluded that male bimaturism is likely to be an evolutionarily stable strategy, in which non-cheek-padded males simply bide their time until periods of rank instability. The methods for genetic analyses used in this research, which was published in September 2015 in the journal Behavioral Ecology and Sociobiology, were developed using faecal samples from the Los Angeles Zoo and Botanical Gardens, CA, St Paul's Como Zoo and Conservatory, MN, and Henry Vilas Zoo in Madison, WI. The study was featured by The Washington Post, Discovery News and The Daily Mail, and profiled on Serious Science. Preliminary findings were originally presented at the 9th Annual Orangutan SSP Husbandry Workshop at the Los Angeles Zoo and Botanical Gardens in August 2013.
Cytokine Production and Urinary Excretion in the Orangutan: Drs. Lyle Moldawer and Erin Vogel are investigating the hypothesis that a high degree of endotoxin-responsiveness and cytokine production is shared by orangutans and humans. Their study seeks (1) to determine cross-reactivity among orangutan cytokines and human immunoassay reagents, (2) to determine ex vivo cytokine production to bacterial endotoxin by whole blood obtained from orangutans, and (3) to measure hemopexin and other acute phase reactant proteins that bind endotoxin (LBP, BPI) in the plasma of orangutan. Click here for project description and information on participation; click here for contact information.
A retrospective study of cardiovascular disease in captive orangutans (Pongo sp.): This study, conducted by Drs. Amanda Marino and Lauren Howard, will provide a systematic review of the current cases of cardiovascular disease diagnosed in captive orangutans pre-mortem. This project will provide an overview of the unique attributes of orangutan physiology and how it may affect cardiac function, as well as how heart disease in orangutans differs from other great apes. Additionally, this paper will act as a source of information on the clinical signs of disease, risk factors of disease, and the current thoughts on how to manage cardiac disease in orangutans. This paper will advance our knowledge of cardiovascular disease and improve our ability to diagnose and treat captive orangutans. Please click here for project details, information on participation, and contact information.
Retrospective Classification and Management Assessment of Canine Fractures in Captive Managed Populations of Great Apes: Jill Moyse, Curator of Primates, Lincoln Park Zoo. At this time, it is unknown how many individual great apes in the captive population have broken, fractured and or cracked canine teeth. As several approaches for treatment or repair are possible, it is not known which of these injuries correlate best with the available management options. Long-term effects of no treatment are not predictable. The retrospective project will survey the captive managed great ape population to assess the occurrence of injuries and what treatment was provided to the animal. Zoo veterinarians will be surveyed to document any great apes in their collection that have any incidents of breakage, cracked or fracture of the canine teeth in the last 10 years. We anticipate majority to full participation from the SSP institutions that house great apes and will be able to compile an inventory of all animals that currently have canine fractures, breaks or cracks, the treatment they received and if any common risk factors are associated with the canine fractures. With this information, it is anticipated that prospective guidance of treatment options can be provided to institutions, veterinarians and the great ape SSP when animals present a fracture, break or cracked canine.
Orangutan fecal microbiome analysis: Stephanie McCain, DVM, Dipl ACZM (Birmingham Zoo), Richard Sim, DVM, Dipl ACZM (Oregon Zoo), and Casey Morrow, PhD (University of Alabama, Birmingham). An inordinate number of zoo housed orangutans have either chronic constipation or chronic diarrhea, with an underlying cause rarely identified. (Nancy Lung, personnal comm.) Many zoos must manage one or both of these conditions, regardless of diet fed, illustrating the need to have a better understanding of orangutan GI health. The goal of this study is to understand how the gut microbe community structure correlates with and can influence the health and behavior of zoo-housed orangutans. In order to accomplish this goal, we plan to perform microbiome analysis on fecal samples from all individual orangutans housed in the United States and evaluate these results against diet, fecal consistency, and pedigree. (Approved January 2020) PENDING ANLYSIS
The influence of plant secondary metabolites on diet selection, nutrition, and health of wild Bornean Orangutans: William Aguado (PhD Candidate, Rutgers University) and Erin Vogel, PhD (Rutgers University & Tuanan Orangutan Research Project). Plant secondary metabolites (PSMs)—the toxic, unpalatable, or otherwise harmful chemical compounds that are produced in plants—are thought to play an important role in determining what primates can and do eat. Orangutans presumably encounter such compounds in their biodiverse environments, yet the role PSMs play in their nutritional ecology is poorly understood. This study examines how a common class of PSM called tannins, inhibits nutrient digestion and influences foraging behavior of Bornean orangutans at the site of Tuanan, in Central Kalimantan, Indonesia. We use behavioral observation, nutritional analysis of plant foods, and urinary biomarkers of nutritional stress to answer these questions. Gaining a better understanding of the chemical predictors of orangutan diet selection can help shed light on their ecology and evolution, contribute to our nutritional prescriptions for these apes in captivity, and help to identify key resources that support wild orangutan populations.
Humor and teasing in great apes: Isabelle Laumer, PhD (Department of Anthropology, UCLA), Prof. Erica Cartmill (Department of Anthropology, UCLA). This study explores the forms and functions of teasing in zoo-living great apes, with a particular focus on playful teasing. Recent developmental studies suggest that non-verbal “playful teasing” is already visible in human infants in the first year of life. The occurrence of playful teasing in preverbal infants suggests that language is not a prerequisite for this behavior and, thus, that it might be present in our closest living relatives. We aim to gather information about the prevalence and types of teasing in zoo-living apes through a questionnaire for ape keepers sent to selected North American and European zoos. The purpose of this study is to systematically assess and identify different forms of teasing behaviors, in which apes try to provoke a social reaction from others. These interactions might resemble games, teasing, harassment, or surprising each other. Furthermore, we hope to better understand which animals (e.g. age classes) typically perform provocative behavior and to whom it is directed. We are also interested in how apes respond to teasing from others. Developing a more complete understanding of the dynamics of positive and negative teasing behaviors will contribute to zoos’ goals of better assessing and managing the complex social dynamics of zoo-housed primates and the findings of this study will make important contributions to comparative psychology and evolutionary biology. NPR Clip
Determination of normal reference intervals for thyroid hormone serum concentrations in orangutans (Pongo sp.): Melissa Fayette, DVM (Indianapolis Zoo), Anneke Moresco, DVM, PhD (Reproductive Health Surveillance Program), Emily Vincent, DVM (The Ohio State University), Brian Petroff, DVM, PhD (Michigan State University), and Dalen Agnew (Michigan State University). Thyroid disease has been reported anecdotally in several orangutans within the SSP population; however, accurate diagnosis of these conditions is hindered by a paucity of published reference intervals for thyroid hormone serum concentrations in this species. Thyroid hormones play a critical role in regulation of growth, metabolism, and reproduction. Excess or deficiency in thyroid hormones may lead to the development of potentially life-threatening conditions such as hypertension, cardiovascular disease, and diabetes and can also result in infertility. Thus, timely detection and treatment of thyroid dysfunction is essential given its potential impact on overall health and breeding success of this critically endangered species. The goal of this study is to establish baseline reference intervals for thyroxine (T4), free-thyroxine (FT4), free triiodothyronine (T3) and thyroid stimulating hormone (TSH) in healthy orangutans using commercially available chemiluminescence immunoassays validated specifically for use in this species and to determine the influence of sex and age on thyroid hormone serum concentrations.
Investigating the Composition of the Milk of Apes: Dr. Mike Power PhD, Mike Maslanka and Erin Stromberg, Smithsonian National Zoo. This is a continuation of ongoing research. The objective is to obtain longitudinal milk samples from apes (bonobos, chimpanzees, gorillas, orangutans, and gibbons), from shortly after birth until the female is no longer lactating, in order to further characterize the nutritional content of ape milk, continue investigating the milk microbiota of non-human primates, and learn more about the potential role of bioactive molecules in mother’s milk to regulate offspring physiology and metabolism (among other questions). Additional milk samples from females whose milk has not previously been collected are important to document the extent to which there are species-specific patterns and the extent of variation between females. To date, samples have been obtained from 3 orangutans and 7 lowland gorillas. We aim to receive samples from 10-12 individuals from each ape species in order to be able to fully characterize variation between females. Results of this work are shared widely for the benefit of zoos worldwide. Samples are available for collaborative research projects.
Development of a database of fetal ultrasound measurements for the creation of orangutan-specific (Pongo spp.) growth curves and determination of parturition dates: Current data is lacking in species specific fetal growth curves and gestation lengths for orangutans. Dr. Brittany Rizzo, along with Connie Warner, Dr. Joe Smith, and Dr. Ric Berlinski, is compiling existing fetal ultrasound and birth date information as well as gathering future information in the hopes of creating more accurate and species-specific fetal growth curves for orangutans. Data of this nature can benefit institutions via improved planning for their training and social structure changes. Additionally, in cases of animals that have had previous difficult births or emergency cesarean sections, accurate determination of gestational age for scheduling future cesarean sections can reduce the risk of complications for both the dam and the infant. Please click here for project description and information on participation; click here for contact information.