Research
Behavioral research helps to answer important questions about optimal animal care and well-being, and improves our ability to meet the husbandry, social, and behavioral needs of the animals in our care. By analyzing behavior, researchers try to develop an understanding of animals’ learning processes, motivations, physical abilities, sensory adaptations and social structure. This information is then used to make decisions about managing animals. Working to understand orangutans’ sensory, cognitive, and physiological abilities can also be applied to conservation strategies, thereby benefiting orangutans in the wild as well.
Research using biomaterials is another important aspect, especially when such studies involve passive or voluntary collection of samples (e.g., urine, feces, hair, milk, recently even blood samples or blood pressure readings, etc.), or materials than can be collected opportunistically during scheduled anesthesia (e.g., body measurements taken during routine scheduled physical examination, collection of biological samples from apes not trained for voluntary collection, etc.).
Behavioral research helps to answer important questions about optimal animal care and well-being, and improves our ability to meet the husbandry, social, and behavioral needs of the animals in our care. By analyzing behavior, researchers try to develop an understanding of animals’ learning processes, motivations, physical abilities, sensory adaptations and social structure. This information is then used to make decisions about managing animals. Working to understand orangutans’ sensory, cognitive, and physiological abilities can also be applied to conservation strategies, thereby benefiting orangutans in the wild as well.
Research using biomaterials is another important aspect, especially when such studies involve passive or voluntary collection of samples (e.g., urine, feces, hair, milk, recently even blood samples or blood pressure readings, etc.), or materials than can be collected opportunistically during scheduled anesthesia (e.g., body measurements taken during routine scheduled physical examination, collection of biological samples from apes not trained for voluntary collection, etc.).
The SSP Research/Biomaterials Request Review Process
Research and biomaterials proposals submitted to the Orangutan SSP are reviewed by the SSP's Steering Committee and Advisors. Proposals are judged primarily on their relevance to the Orangutan SSP program. The reviewers' determination will be:
No Objection/Relevant to SSP;
No Objection/Not Relevant to SSP;
or
SSP Objection.
The SSP's determination does not compel individual zoos to participate, nor does it preclude participation. Many zoos require review by their own internal research approval process regardless of the SSP's stance. The SSP's determination is valid for three years from the date of notification, after which continuing proposals must be resubmitted for review.
The SSP's application form intentionally mirrors the Standardized Research Proposal form developed by the AZA's Research and Technology Committee.
Applicants will be notified of the Steering Committee's majority determination within 6 weeks of submission of a complete application.
Click here to download the Orangutan SSP Research Proposal Form.
Click here for Grant Funding information and Application
Why Submit Your Research Proposal to the SSP?
Some studies can be accomplished by collecting data on just a few individuals, and in those cases, researchers may choose to work directly with their local zoo for access to orangutans. Many research projects, however, benefit from the inclusion of data from a large number of individuals. In those cases, working through the Orangutan SSP can be of significant benefit to the scientist because of the broader awareness and encouragement of the SSP. Additionally, for some zoos, SSP review is a prerequisite to acceptance through their own internal research approval process. SSP review can also be beneficial in obtaining outside funding for research projects. Note, however, that the SSP's determination does not compel individual zoos to participate, nor does absence of SSP review preclude participation.
Research and biomaterials proposals submitted to the Orangutan SSP are reviewed by the SSP's Steering Committee and Advisors. Proposals are judged primarily on their relevance to the Orangutan SSP program. The reviewers' determination will be:
No Objection/Relevant to SSP;
No Objection/Not Relevant to SSP;
or
SSP Objection.
The SSP's determination does not compel individual zoos to participate, nor does it preclude participation. Many zoos require review by their own internal research approval process regardless of the SSP's stance. The SSP's determination is valid for three years from the date of notification, after which continuing proposals must be resubmitted for review.
The SSP's application form intentionally mirrors the Standardized Research Proposal form developed by the AZA's Research and Technology Committee.
Applicants will be notified of the Steering Committee's majority determination within 6 weeks of submission of a complete application.
Click here to download the Orangutan SSP Research Proposal Form.
Click here for Grant Funding information and Application
Why Submit Your Research Proposal to the SSP?
Some studies can be accomplished by collecting data on just a few individuals, and in those cases, researchers may choose to work directly with their local zoo for access to orangutans. Many research projects, however, benefit from the inclusion of data from a large number of individuals. In those cases, working through the Orangutan SSP can be of significant benefit to the scientist because of the broader awareness and encouragement of the SSP. Additionally, for some zoos, SSP review is a prerequisite to acceptance through their own internal research approval process. SSP review can also be beneficial in obtaining outside funding for research projects. Note, however, that the SSP's determination does not compel individual zoos to participate, nor does absence of SSP review preclude participation.
Current Projects
Each of the following research projects has been reviewed by the Steering Committee, and SSP-member zoos are encouraged to participate in these studies. Projects are updated on an annual basis for progress and status.
You can find pending results and completed projects here.
The Orangutan SSP supports the Great Ape Heart Project, an IMLS-funded project to design an innovative and coordinated national program to investigate ape cardiovascular disease (CVD) and establish uniform, state of the art cardiac diagnosis, treatment and prevention strategies for great ape CVD.
Growth and Development in Captive Juvenile Orangutans Faye Harwell (PhD Candidate at Boston University) & Cheryl Knott, PhD (Boston University & Gunung Palung Orangutan Project). Next to humans, orangutans have the slowest life history amongst primates starting with a long juvenile period. Despite many years of study, little is known about the timing of development in orangutans, the relationship between energetics and growth, the association between sex steroids and developmental events, and the relationship between flanging and skeletal growth. This study will examine growth and development in captive orangutans and fill some of these gaps in our knowledge of this critically endangered great ape. We hope to study the process of flanging for participants that begin flange development during data collection. Methods for this study include collecting urine samples for hormone analyses, taking photographs of the participants’ forearms and facial profiles to estimate growth, and examining historical weight records to assess changes in overall body size. Please contact Faye Harwell or Cheryl Knott with any questions or inquiries about the study. (Renewed July 2022)
Investigating a Genetic Basis for Chronic Respiratory Disease in orangutans The objective of this study is to establish whether there is a genetic cause for orangutan respiratory disease syndrome (ORDS), the chronic lung and sinus disease that decreases the quality of life and increases the rate of death in orangutans. In our previous study, we identified a nonsense mutation (c.484A>T) in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene in heterozygosity in an asymptomatic male and in his sire and offspring. We further demonstrated that the resulting protein from this nonsense mutation was absent when it was introduced in HEK293 cells, and that c.484A>T messenger RNA was severed reduced in nasal epithelial cells from the orangutan, suggesting that this mutation is potentially lethal if combined with another severe CFTR mutation. Finally, we demonstrated the lack of CFTR mutations in an affected male and his affected father. Link to our publication in the American Journal of Primatology is here: https://onlinelibrary.wiley.com/doi/abs/10.1002/ajp.23097 These results suggest that whole genome sequencing could help us better understand if gene abnormalities track with disease. Dr. Taylor-Cousar will carefully review the medical and pedigree records of all orangutans with chronic sinopulmonary disease and those of his/her living and deceased relatives in order to correctly phenotype ORDS-affected and unaffected orangutans. We will collect blood and tissue samples from orangutans at participating zoos for analysis. If it is established that chronic respiratory disease in orangutans is a result of gene abnormalities, this information can be used to guide the use of therapies and breeding decisions in the orangutan population. This research is being led by Dr. Jennifer Taylor-Cousar in collaboration with colleagues at Johns Hopkins University. For questions regarding project participation, please contact Dr. Taylor-Cousar (Renewed April 2022)
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. (Reviewed September 2021)
Captive Orangutan Dentition Emergence: Felicity Oram is investigating tooth emergence in orangutans. The specific primary objective is to provide a comprehensive updated tooth emergence chart for both species. The need is for more consistent and specific age assignment to better serve husbandry and rehabilitation of orphans and to help build stronger cases for enforcement of existing laws that protect these endangered species in range countries. Additionally, this will provide zoos with a useful updated resource of baseline normals for tooth emergence. Since orangutans are a slow-growing long-lived species of a semi-solitary nature many zoos hold only a few individuals so the benefit of accumulated knowledge in a simple format will be useful for husbandry and veterinary care of zoo residents. Please review the project proposal and the report form for more information; click here for contact information. (Renewed June 2021)
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. (Renewed June 2021)
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. (Renewed May 2021)
Exploring the microstructure and fracture resistance of tooth enamel from Pongo pygmaeus: Cameron Renteria (PhD Candidate, University of Washington), Izabela Carpenter (University of Washington), *Dwayne Arola, PhD (University of Washington). Tooth enamel requires tolerance to damage and resistance to fracture. In mammalian teeth, the microstructure of enamel prevents cracks at the tooth’s surface from causing tooth fracture. The secret to this quality is a special pattern of the enamel rod distribution known as decussation. Vogel et al. [2008] reported that the enamel of Pongo molar teeth exhibits an “optimized” microstructure that enables their diet to include harder and tougher materials without causing tooth fracture. That special quality could enable their teeth to endure the comparatively larger bite forces required for their diet relative to other mammals. This study examines the tooth enamel of Pongo and other orangutans using spectroscopy, microscopy and other tools to determine the composition, microstructure and mechanical properties relevant to the crack growth resistance. These efforts will provide new understanding of enamel microstructure in orangutans and could inspire the design of next generation engineering materials with an unparalleled level of damage tolerance. (Reviewed April 2021)
Great Ape Neuroscience Project: The goal of the Great Ape Neuroscience Project is to investigate the neurobiological basis of variation that distinguishes great apes from other primates, defines each great ape species as unique, and helps us to better understand humans’ place in nature. The Great Ape Neuroscience Project originated as an extension of the Great Ape Aging Project (funded by the National Institute on Aging of the National Institutes of Health). The Great Ape Aging Project was conceived of as a means of adding scientific value to elderly apes in captivity. Medical scientists studying the causes of neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases expressed interest in studies of brain and behavior in great apes to determine whether or not the same neurodegenerative processes occurred in them as in afflicted humans. The convergence of these interests and needs led to the development of the Great Ape Aging Project in 1997. This project seeks whole fixed brains from great apes (and other primates) at necropsy. Several documents describe the project and its requirements: Great Ape Neuroscience Project 2011 Progress Report; Project description; TAG project approval letter; Detailed brain collection and submission instructions. Bibliography of articles related to this project. Contact: William Hopkins or Chet Sherwood (Renewed February 2021)
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. (Reviewed January 2021)
Tannin-Binding Salivary Proteins in Apes: William Aguado (PhD Candidate, Rutgers University), Meredith Bastian (Proceedings of the National Academy of Sciences) Erin Vogel, PhD (Rutgers University & Tuanan Orangutan Research Project). Foraging primates are faced with acquiring adequate nutrition from plants while simultaneously overcoming the challenges posed by plant secondary metabolites (PSMs) – the often toxic, unpalatable, or otherwise harmful chemical compounds that plants produce. PSMs are considered a selective force acting on primate physiology and primates should evolve physiological mechanisms for combatting commonly encountered PSMs. As part of a larger project exploring the relationship between PSMs and the feeding behavior, nutrition, and health of Bornean orangutans (Pongo pygmaeus wurmbii), this research examines whether orangutans have physiological adaptations to a diet rich in tannins – a common class of PSMs known for being toxic and inhibiting digestion. Our goal is to collect saliva from orangutans housed at AZA accredited zoos to see if, and to what extent, orangutans produce tannin-binding salivary proteins as a defense against tannins. We are particularly interested in proline-rich-salivary proteins (PRPs), which are thought to be produced in the saliva of some mammals to bind tannins and decrease their ability to inhibit protein digestion. Once saliva is collected, we will screen for PRPs, measure their abundance in orangutan saliva, and measure their tannin-binding capacity. Knowing the extent to which orangutans produce PRPs will help to explain orangutan diet selection in the wild and increase our understanding of orangutan physiology. (Reviewed December 2020)
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. (Approved October 2020)
Retrospective assessment of peri-anesthetic mortality and associated risk factors of great apes among zoological collections in the United States over a 10 year period: Julie Balko, VMD, DACVAA (NC State University, College of Veterinary Medicine), Sathya Chinnadurai, DVM, Ms, DACZM, DACVAA, DACAW (St. Louis Zoo), and Jb Minter, MS, DVM, DACZM (North Carolina Zoo). This project will retrospectively assess peri–anesthetic mortality risk and associated risk factors of great ape species among zoological collections within the United States over a 10 year period. Great apes are commonly found in professional care settings in the United States and are frequently anesthetized for diagnostic and therapeutic purposes. While great ape peri–anesthetic mortality risk has been investigated among zoological collections in the UK and Ireland, no multi-institutional studies have been conducted among collections in the United States and the few published single institution studies were conducted greater than 20 years ago. As great ape anesthetic management has changed greatly within this time frame (eg, anesthetic drug protocols, anesthetic monitoring capabilities), investigation of current peri–anesthetic mortality risk and associated risk factors among multiple zoological collections within the United States is imperative. This data is of immense clinical relevance and will not only help guide anesthetic management of great ape species but will ultimately help reduce anesthetic morbidity and mortality of these endangered animals. (Reviewed June 2020)
Each of the following research projects has been reviewed by the Steering Committee, and SSP-member zoos are encouraged to participate in these studies. Projects are updated on an annual basis for progress and status.
You can find pending results and completed projects here.
The Orangutan SSP supports the Great Ape Heart Project, an IMLS-funded project to design an innovative and coordinated national program to investigate ape cardiovascular disease (CVD) and establish uniform, state of the art cardiac diagnosis, treatment and prevention strategies for great ape CVD.
Growth and Development in Captive Juvenile Orangutans Faye Harwell (PhD Candidate at Boston University) & Cheryl Knott, PhD (Boston University & Gunung Palung Orangutan Project). Next to humans, orangutans have the slowest life history amongst primates starting with a long juvenile period. Despite many years of study, little is known about the timing of development in orangutans, the relationship between energetics and growth, the association between sex steroids and developmental events, and the relationship between flanging and skeletal growth. This study will examine growth and development in captive orangutans and fill some of these gaps in our knowledge of this critically endangered great ape. We hope to study the process of flanging for participants that begin flange development during data collection. Methods for this study include collecting urine samples for hormone analyses, taking photographs of the participants’ forearms and facial profiles to estimate growth, and examining historical weight records to assess changes in overall body size. Please contact Faye Harwell or Cheryl Knott with any questions or inquiries about the study. (Renewed July 2022)
Investigating a Genetic Basis for Chronic Respiratory Disease in orangutans The objective of this study is to establish whether there is a genetic cause for orangutan respiratory disease syndrome (ORDS), the chronic lung and sinus disease that decreases the quality of life and increases the rate of death in orangutans. In our previous study, we identified a nonsense mutation (c.484A>T) in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene in heterozygosity in an asymptomatic male and in his sire and offspring. We further demonstrated that the resulting protein from this nonsense mutation was absent when it was introduced in HEK293 cells, and that c.484A>T messenger RNA was severed reduced in nasal epithelial cells from the orangutan, suggesting that this mutation is potentially lethal if combined with another severe CFTR mutation. Finally, we demonstrated the lack of CFTR mutations in an affected male and his affected father. Link to our publication in the American Journal of Primatology is here: https://onlinelibrary.wiley.com/doi/abs/10.1002/ajp.23097 These results suggest that whole genome sequencing could help us better understand if gene abnormalities track with disease. Dr. Taylor-Cousar will carefully review the medical and pedigree records of all orangutans with chronic sinopulmonary disease and those of his/her living and deceased relatives in order to correctly phenotype ORDS-affected and unaffected orangutans. We will collect blood and tissue samples from orangutans at participating zoos for analysis. If it is established that chronic respiratory disease in orangutans is a result of gene abnormalities, this information can be used to guide the use of therapies and breeding decisions in the orangutan population. This research is being led by Dr. Jennifer Taylor-Cousar in collaboration with colleagues at Johns Hopkins University. For questions regarding project participation, please contact Dr. Taylor-Cousar (Renewed April 2022)
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. (Reviewed September 2021)
Captive Orangutan Dentition Emergence: Felicity Oram is investigating tooth emergence in orangutans. The specific primary objective is to provide a comprehensive updated tooth emergence chart for both species. The need is for more consistent and specific age assignment to better serve husbandry and rehabilitation of orphans and to help build stronger cases for enforcement of existing laws that protect these endangered species in range countries. Additionally, this will provide zoos with a useful updated resource of baseline normals for tooth emergence. Since orangutans are a slow-growing long-lived species of a semi-solitary nature many zoos hold only a few individuals so the benefit of accumulated knowledge in a simple format will be useful for husbandry and veterinary care of zoo residents. Please review the project proposal and the report form for more information; click here for contact information. (Renewed June 2021)
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. (Renewed June 2021)
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. (Renewed May 2021)
Exploring the microstructure and fracture resistance of tooth enamel from Pongo pygmaeus: Cameron Renteria (PhD Candidate, University of Washington), Izabela Carpenter (University of Washington), *Dwayne Arola, PhD (University of Washington). Tooth enamel requires tolerance to damage and resistance to fracture. In mammalian teeth, the microstructure of enamel prevents cracks at the tooth’s surface from causing tooth fracture. The secret to this quality is a special pattern of the enamel rod distribution known as decussation. Vogel et al. [2008] reported that the enamel of Pongo molar teeth exhibits an “optimized” microstructure that enables their diet to include harder and tougher materials without causing tooth fracture. That special quality could enable their teeth to endure the comparatively larger bite forces required for their diet relative to other mammals. This study examines the tooth enamel of Pongo and other orangutans using spectroscopy, microscopy and other tools to determine the composition, microstructure and mechanical properties relevant to the crack growth resistance. These efforts will provide new understanding of enamel microstructure in orangutans and could inspire the design of next generation engineering materials with an unparalleled level of damage tolerance. (Reviewed April 2021)
Great Ape Neuroscience Project: The goal of the Great Ape Neuroscience Project is to investigate the neurobiological basis of variation that distinguishes great apes from other primates, defines each great ape species as unique, and helps us to better understand humans’ place in nature. The Great Ape Neuroscience Project originated as an extension of the Great Ape Aging Project (funded by the National Institute on Aging of the National Institutes of Health). The Great Ape Aging Project was conceived of as a means of adding scientific value to elderly apes in captivity. Medical scientists studying the causes of neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases expressed interest in studies of brain and behavior in great apes to determine whether or not the same neurodegenerative processes occurred in them as in afflicted humans. The convergence of these interests and needs led to the development of the Great Ape Aging Project in 1997. This project seeks whole fixed brains from great apes (and other primates) at necropsy. Several documents describe the project and its requirements: Great Ape Neuroscience Project 2011 Progress Report; Project description; TAG project approval letter; Detailed brain collection and submission instructions. Bibliography of articles related to this project. Contact: William Hopkins or Chet Sherwood (Renewed February 2021)
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. (Reviewed January 2021)
Tannin-Binding Salivary Proteins in Apes: William Aguado (PhD Candidate, Rutgers University), Meredith Bastian (Proceedings of the National Academy of Sciences) Erin Vogel, PhD (Rutgers University & Tuanan Orangutan Research Project). Foraging primates are faced with acquiring adequate nutrition from plants while simultaneously overcoming the challenges posed by plant secondary metabolites (PSMs) – the often toxic, unpalatable, or otherwise harmful chemical compounds that plants produce. PSMs are considered a selective force acting on primate physiology and primates should evolve physiological mechanisms for combatting commonly encountered PSMs. As part of a larger project exploring the relationship between PSMs and the feeding behavior, nutrition, and health of Bornean orangutans (Pongo pygmaeus wurmbii), this research examines whether orangutans have physiological adaptations to a diet rich in tannins – a common class of PSMs known for being toxic and inhibiting digestion. Our goal is to collect saliva from orangutans housed at AZA accredited zoos to see if, and to what extent, orangutans produce tannin-binding salivary proteins as a defense against tannins. We are particularly interested in proline-rich-salivary proteins (PRPs), which are thought to be produced in the saliva of some mammals to bind tannins and decrease their ability to inhibit protein digestion. Once saliva is collected, we will screen for PRPs, measure their abundance in orangutan saliva, and measure their tannin-binding capacity. Knowing the extent to which orangutans produce PRPs will help to explain orangutan diet selection in the wild and increase our understanding of orangutan physiology. (Reviewed December 2020)
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. (Approved October 2020)
Retrospective assessment of peri-anesthetic mortality and associated risk factors of great apes among zoological collections in the United States over a 10 year period: Julie Balko, VMD, DACVAA (NC State University, College of Veterinary Medicine), Sathya Chinnadurai, DVM, Ms, DACZM, DACVAA, DACAW (St. Louis Zoo), and Jb Minter, MS, DVM, DACZM (North Carolina Zoo). This project will retrospectively assess peri–anesthetic mortality risk and associated risk factors of great ape species among zoological collections within the United States over a 10 year period. Great apes are commonly found in professional care settings in the United States and are frequently anesthetized for diagnostic and therapeutic purposes. While great ape peri–anesthetic mortality risk has been investigated among zoological collections in the UK and Ireland, no multi-institutional studies have been conducted among collections in the United States and the few published single institution studies were conducted greater than 20 years ago. As great ape anesthetic management has changed greatly within this time frame (eg, anesthetic drug protocols, anesthetic monitoring capabilities), investigation of current peri–anesthetic mortality risk and associated risk factors among multiple zoological collections within the United States is imperative. This data is of immense clinical relevance and will not only help guide anesthetic management of great ape species but will ultimately help reduce anesthetic morbidity and mortality of these endangered animals. (Reviewed June 2020)