Kay E. Holekamp - US grants

The occurrence of sibling rivalry has now been documented in many species of animals, including humans. Mammalian sibling rivalry is widely believed to be less deadly than that among avian brood mates. The broad goal of the current research is to evaluate the generality of existing sibling rivalry theory by exploring sibling conflict in mammals. The work will focus specifically on one species of gregarious mammal, the spotted hyena, in which sibling rivalry is more intense than is that described in other mammals. A combination of techniques, including behavioral observation, monitoring of excreted hormone levels, and fetal ultrasonography, will be used to determine whether siblicide occurs facultatively or obligately in free-living hyenas in Kenya. The influence of hormones on dispersal will also be addressed.

Siblings are often each other's closest associates and closest competitors, so they often bear the heaviest costs of selfish behavior. Because the best interests of rival siblings need not necessarily coincide with those of their parents, conflict between parents and
offspring often affects the form and outcome of sibling competition. The study of sibling rivalry is thus of great significance for understanding the occurrence of both selfish and altruistic behaviors among close kin in our own species and in other animals.

LTREB: Integrated study of behavioral and morphological development in free-living carnivores
Proposal #IBN0113170

Kay E. Holekamp
Barbara L. Lundrigan
Kim T. Scribner

Spotted hyenas (Crocuta crocuta) are long-lived, gregarious carnivores exhibiting a unique suite of behavioral, endocrine, and morphological characteristics. Since 1988, Dr. Holekamp and associates have been studying the behavioral ecology of members of one large spotted hyena population in Kenya, focusing mainly on the development of social behavior. Age, sex, kin relations, and social status are known for all natal animals in the study population, and social histories are known for all hyenas under 13 years of age. Most adult clan members of both sexes wear radio collars so they can be regularly located and observed. The proposed LTREB project will support new aspects of long-term research with this study population. Specifically, Dr. Holekamp will join forces with a morphometrician (Dr. Lundrigan) and a geneticist (Dr. Scribner) to achieve three new goals. (1) First, a novel combination of behavioral and morphometric techniques will be used to examine age-related changes in morphology of the feeding apparatus, diet, feeding behavior, and feeding performance. This portion of the proposed work will include documentation (with new and archived data) of age-related change in chewing, foraging, feeding behavior, and diet; administration of simple performance tests in the field to assess maximal feeding capabilities at each age; and quantitative analysis of age-related changes in skull morphology. (2) The second goal is to start monitoring behavior, growth, and demography in a second spotted hyena population (one less exposed to humans) to inquire whether age-related constraints on foraging abilities might make certain age-sex classes of hyenas more vulnerable than others to effects of anthropogenic disturbance. (3) Finally, in both hyena populations, genetic markers, in conjunction with behavioral data, will be used to elucidate the relationship between behavioral responses to anthropogenic disturbance and fitness decrements associated with such disturbance.
The proposed work will shed considerable light on the natural and anthropogenic selection pressures acting on hyenas during each stage of life. It will also combine several different data types, all collected in a natural ecological and evolutionary context, to integrate traditionally disjunct approaches to the study of life history evolution. The results should be important not only for understanding the unique suite of traits expressed by spotted hyenas, but more generally, for understanding the role of age-related constraints in the evolution of behavior. With the data from the two different hyena study populations, it will be possible to quantify the effects of anthropogenic disturbance concurrently on both behavior and fitness, identify ecological variables that might be responsible for population differences, and assess the relative effects of these variables on animals in different age, sex, and rank classes. This is a unique opportunity to document the adaptive consequences of behavioral change in response to human activity. It is hoped that the proposed work will serve as a model for understanding the complex relationships among behavior, morphology, fitness, demography, and human disturbance in other mammalian carnivores, including those that are rare and endangered.

Mammalian behavioral development under contrasting regimes of interspecific competition.

Proposal # IBN0343381

PIs: Kay E. Holekamp, Michigan State University
Laura Smale, Michigan State University
Jeffrey A. French, University of Nebraska at Omaha


NON-TECHNICAL ABSTRACT

Little is currently known about how the tendency to engage in risky behavior varies across the life-span in mammals, or how the behavior of young mammals varies with ecological circumstances. In most parts of Africa, lions (Panthera leo) and spotted hyenas (Crocuta crocuta) are the most common large carnivores, and these two species compete regularly for food. Here hypotheses will be tested suggesting that risk-sensitive behavior exhibited by free-living hyenas is affected by age and by competitive interactions with lions. Naturally-occurring variation will be documented in ranging behavior, vigilance, and risky behaviors shown by hyenas during interactions with lions over food. In addition, two playback experiments will inquire how age and local lion density influence hyenas' decisions regarding whether to approach or avoid recorded lion roars when these are broadcast from a hidden speaker. Concentrations of excreted stress hormones will be measured in hyena feces to determine whether stress physiology in these animals is affected by age or by local competition with lions. Measures of naturally-occurring behavior, experimental results, and hormone concentrations will be compared among hyenas at three different developmental stages in two Kenyan national parks in which ratios of resident hyenas to lions differ greatly. Finally, in collaboration with the Kenya Wildlife Service, methods will be developed for effective monitoring of large carnivores, and these methods will later be applied in several other national parks in Kenya. This research will thus combine strong basic science focused on behavioral development with direct applications to management and conservation of large African carnivores, including those that are rare and endangered.

Little is currently known about how the physical development of a young mammal interacts with social and ecological forces at work in the youngsters environment to affect, not only its own performance in ecologically important tasks, but also the behavior exhibited by its parents. This research will investigate this interaction in carnivorous mammals that consume hard foods like bones. The ability to ingest hard foods requires a relatively massive skull that can withstand forces that might otherwise lead to bending or breakage of the bones of the head and jaws. The research will test an hypothesis suggesting that this type of unusually robust skull takes an exceptionally long time to develop as young carnivores mature, that this slow development prevents youngsters from optimizing feeding performance at a young age compared to species that eat softer foods, and that compensatory parental behavior evolves as a consequence so parents can help their young feed until the skull is more fully formed. A second hypothesis that will be tested suggests that the effects of slow skull development are exacerbated by the social environment in which the youngster must feed itself. Specifically, when feeding competition is intense, extreme compensatory adaptations may be expressed in parents. By combining field and laboratory studies, these hypotheses will be tested with a comparative analysis of skull development, feeding performance, feeding competition, and parental behavior in two bone-crushing species, the spotted hyena and the striped hyena. Spotted hyenas are gregarious and their feeding competition is intense, but striped hyenas are solitary. The patterns of development in morphology and performance will be compared in these two hyenas with those in several other carnivores that are not adapted for crushing bones. This work will provide a great deal of information about the evolutionary relationship between morphological development and behavior. The study will also generate much new information about the biology of the striped hyena, one of the few large carnivores about which very little is currently known. The study will thus fill a major gap in carnivore biology, and provide critical information for the conservation of these animals. Furthermore, this research will continue to train American and Kenyan graduate students, teach a study abroad course each year on the behavioral ecology of African mammals, and offer U.S. undergraduates unique opportunities to gain research experience at the interface between behavior and morphology.

This award is co-funded by the Office of International Science and Engineering

Little is known about the effects of prenatal hormone exposure on offspring fitness in natural populations. Therefore, the primary goal of this project is to determine how brief exposure to varying concentrations of male hormones (androgens) before birth influences subsequent behavior, survival and reproduction in free-living mammals, using spotted hyenas in Kenya as model animals. Preliminary data suggest that androgens, like testosterone, may have opposing effects in female hyenas such that aggressiveness is enhanced while fertility is compromised. In this study, investigators will follow into adulthood cubs born to mothers with known concentrations of androgens during late pregnancy, and manipulate androgen concentrations to which young hyenas are exposed in the womb, to determine how long androgen-mediated effects endure, and whether prenatal hormone exposure influences survival and reproduction. This work will provide a novel and comprehensive picture of both immediate and long-term effects of early androgen exposure as the investigators follow focal hyenas from birth to adulthood, and closely monitor survival and reproduction in multiple generations. The results of this study will be important, not only for understanding the unique traits of spotted hyenas, but also for understanding more broadly the role of prenatal hormone exposure in the generation of natural variation in morphology and behavior, and the role of opposing androgen effects in the evolution of mammalian life histories. This research offers unique and highly valuable training opportunities for American students in an international environment. The investigators will also continue training Kenyan graduate students, supporting Masai students in rural elementary schools, working closely with the public media, maintaining their educational website, and giving many lectures each year to lay audiences. In addition, they will make core data from this long-term project available to other scientists and the general public through two web portals.

Animals contain billions of bacteria and most benefit the health of their animal hosts. Currently, the effects of symbiotic bacteria on the behavior of their animal hosts remain largely unexplored. Symbiotic bacteria potentially figure prominently in animal communication, especially among mammals. Many mammals communicate by scent-marking with products of specialized glands. These glands are highly conducive to bacterial proliferation, and it has been postulated that the volatile odorants the bacteria generate are used by their hosts in communication. This project uses current insights and tools of microbial ecology to elucidate the effects of symbiotic bacteria on the scent-marking system of the spotted hyena, a socially complex large carnivore found throughout Sub-Saharan Africa. Scent discrimination experiments with hyenas in Kenya will illustrate the information content of hyenas' scent-marks. Chemical analyses will further illustrate the information content of their marks and also reveal how that information is chemically coded. Culture-independent molecular surveys of the same scent-marks will indicate whether variation in symbiotic bacterial communities underlies the coding of information in scent-marks. Lastly, contemporary culturing techniques will be used to isolate prominent members of scent gland bacterial communities, and to ascertain whether they produce the odorants that, as indicated by the chemical analyses, likely code information in scent-marks. This project will enhance our understanding of the potential roles of bacteria in mammalian chemical communication systems. The project will involve the training of undergraduates across disciplinary boundaries, integrating cutting-edge advances in molecular biology into animal behavior research. It will result in public access to over one million molecular sequences from an entirely novel symbiotic environment, and should stimulate multi-disciplinary partnerships to generate a central online database enabling rapid access to molecular sequences from symbiotic systems. This project should be transformative, opening up a rich new field of study and altering our perceptions of symbiotic bacteria and the behavior of their animal hosts.

0965840
Holekamp
Michigan State University

IRES: U.S.-Kenya Behavioral Ecology and Conservation of African Carnivores

Michigan State University (MSU) Distinguished Professor Kay Holekamp will launch a 3-year International Research Experience for Students (IRES) project that builds on a strong, well-established scientific program of carnivore research in Kenya. Each year, four top US undergraduates will be selected from a nation-wide pool of applicants to conduct field research on spotted hyenas and other African carnivores. There is no other comparable field research-training program available that offers US undergraduate students the chance to study the biology of free-living African carnivores in one of the world's most magnificent game parks.

The IRES students will help expand the current research focus from single-species to a much richer comparative analysis of multiple sympatric species that inhabit the Mara-Serengeti ecosystem; IRES will also foster a training partnership with three highly experienced Kenyan scientists at the Kenya Wildlife Service (KWS), Nairobi, all of whom will mentor the US students. Aided by the mentoring team, the students will address a broad array of hypothesis- driven research questions about the behavior, conservation and physiology of African carnivores, ranging from the evolution of their cognitive abilities to anthropogenic effects on their stress physiology.

Before departure, students will participate in a rigorous web-based research and cultural orientation, and Swahili language training. In-country, they will train initially at the Kenya Wildlife Service HQ, and then transit to the tented research camp in the Masai Mara National Reserve where they will spend seven weeks developing and executing the research. Before leaving Kenya, the students will present their work at the Carnivore Researchers Conference held each year at the KWS HQ.

The research opportunities offered here are unparalleled, not only to investigate the biology of several carnivore species that remain poorly understood, but also to make important contributions in the intellectual domains of behavioral ecology, stress physiology, and conservation biology. It is expected that IRES student research will shed considerable new light on the basic mechanisms by which African carnivores interact with their environments and with one another. This newly acquired knowledge will be widely disseminated via conference presentations and publication in professional journals, and will be applied directly to carnivore management and conservation efforts in Kenya. For reference: http://www.naturalscience.msu.edu/students/undergraduate/enhance_your_experience/undergraduate_research/index.html

Additionally, participants in IRES will learn a great deal about African life and culture, and about the complexities associated with carnivore conservation in a developing country. By fostering long-lasting friendships and collaborations between Kenyans and Americans, this experience will contribute significantly to the development of a new generation of global scientists who are united in their desire to understand and protect the natural world.

The Bio/computational Evolution in Action CONsortium (BEACON) is a Science and Technology Center (STC) that enables research on evolutionary dynamics in natural and artificial systems and training of multi-disciplinary scientists in bio/computation, with a unique focus on the intersection of evolutionary biology, computer science, and engineering. The Center will enhance the development of applications of computational methods in biology, the use of artificial intelligence in computer science, and the enhancement of genetic algorithms in engineering design. Evolution by natural selection defines an algorithmic approach to finding solutions for complex problems; computer scientists and engineers have harnessed similar algorithms to a diversity of challenges that require optimization over multiple competing dimensions. Likewise, biologists have begun to employ digital modeling of the evolutionary process to examine evolution of complex biological structures and patterns in areas such as paleontology and the gene networks, which defy experimental manipulation in vivo. The Center will promote these interdisciplinary efforts by coordinating activities through three thrust groups: (1) Evolution of Genomes, Networks, and Evolvability, (2) Evolution of Behavior and Intelligence, and (3) Evolution of Communities and Collective Dynamics.

This center has the potential to transform both biology and computational sciences by developing digital experiments to test and apply fundamental principles of evolutionary biology. The possible impacts will be far reaching: from cyber-security to everyday computing applications, from the evolution of disease resistance to the self-organization of social behavior. The BEACON center will train the next generation of interdisciplinary scientists and educate the public about evolution and its role in solving real-world problems through significant educational outreach for K12 students and science museums.

How organisms adapt to changing environments is a question that pervades all biological disciplines and is especially relevant given the pace of global climate change. Hormone concentrations are highly sensitive to environmental variation. In mammalian species, early exposure to hormones can have profound implications on offspring physiology, growth rates, and behavior. The goal of this project is to examine how the hormonal responses of wild red squirrels to environmental variation can adaptively modify offspring due to variable hormone exposure before birth. Red squirrels are an ideal study system to determine the importance of the endocrine system in adapting to changing environments because the survival and future reproduction of offspring can be monitored.
The proposed research will integrate ecology, physiology, and evolution to understand the mechanisms by which animals can adapt to changing environments. Broader impacts include furthering our understanding about how organisms living at northern latitudes can respond to global climate change, training undergraduate students in field data collection as well as allowing them to participate in their own independent research projects, and continuing outreach activities with local aboriginal and underrepresented groups in the Yukon, Canada.

The societies of many mammals are structured by dominance hierarchies in which individual social rank determines priority of access to resources. Although high social rank is known to affect survival and reproduction among female mammals, its effects upon males are poorly understood because males usually change social groups before breeding, so it is difficult to follow them throughout the lifespan. This research follows male carnivores throughout the lifespan to test hypotheses suggesting that their maternal rank in their natal social group might affect the development of their behavior, their body condition and/or their morphology, and that each of these in turn might affect their survival and reproduction in the natural habitat. This research uses spotted hyenas as model mammals because their societies are rigidly structured by dominance relationships. Specially designed radio collars will be applied to male hyenas dispersing among multiple study groups in Kenya. Methods will include radio tracking of collared males, noninvasive monitoring of their stress hormones, and collection of observational data on their performance in standardized test situations as well as their behavioral interactions with other individuals, using bush vehicles as mobile blinds. These techniques will permit determination of whether or not social rank in the natal group affects male survival and reproductive success long after they leave their natal groups, and if so, how such effects are mediated physiologically. This field project offers unique, rare and highly valuable training opportunities for American graduate and undergraduate students in eastern Africa. In addition, this research will educate and entertain lay audiences via internet coverage, public lectures, museum exhibits and television coverage. Finally this work is expected to enhance efforts focused on the conservation of large mammalian carnivores, both in Africa and around the globe.

Current understanding of the long-term effects of prenatal hormone exposure on offspring fitness in natural populations is extremely limited, particularly in viviparous species. The proposed research investigates the fitness consequences of prenatal androgen exposure in a long-lived mammalian carnivore, the spotted hyena. Wild hyenas are studied in Kenya to document correlates and consequences of naturally-occurring variation in early androgen exposure. Cubs born to mothers with known concentrations of androgens during pregnancy are followed into adulthood to test a hypothesis suggesting that androgen-induced variation in cub behavior and morphology is associated with variation in fitness. Two other competing hypotheses are also evaluated, each suggesting different extents to which opposing hormone effects might constrain adaptive evolution. This work will permit uniquely integrated study in long-lived mammals of the development of hormonally-induced traits, from their induction in the womb to their consequences in natural populations. It will be important for understanding more broadly the role of prenatal androgen exposure in the generation of variation in behavior and morphology, and the role played by androgens in the evolution of mammalian life histories. This research crosses disciplinary boundaries and offers unique and highly valuable international training opportunities for American students. The work also trains Kenyan students, and supports Masai students in local elementary schools near the study site. In addition, project personnel work closely with the public media in the USA and abroad, maintain an educational website, and give many lectures each year to lay audiences. Finally, via a web portal this research makes available to other researchers and the general public core data tables in a database that documents hyena behavior, demography, and physiology at the study site since 1988. This project is jointly supported by the Animal Behavior Program and International Science and Engineering.

Title: IRES: International research experience for students on the behavioral ecology and conservation of African carnivores

Nontechnical abstract
This international research training program allows advanced undergraduates and junior graduate students to spend extended periods conducting field research on free-living African carnivores in Kenya, building on a strong long-term program of carnivore research in the Masai Mara National Reserve. Several students each year will undertake projects designed to acquire new and useful information about the carnivores inhabiting the Mara-Serengeti ecosystem, and to develop strong, long-lasting professional relationships with Kenyan scientists. A strong team of American and Kenyan trainers will help students address a broad array of research questions about the behavior, conservation and physiology of African carnivores, ranging from the evolution of their cognitive abilities to the effects of human activity on their stress physiology. Pairs of undergraduate and graduate students will be linked by topical research focus, and work closely with local experts. While in Kenya, students will receive explicit training in science writing, and present their work at an annual conference on carnivore biology sponsored by the Kenya Wildlife Service. The research opportunities offered to students here are unparalleled, not only to investigate the biology of several carnivore species that remain very poorly understood, but also to make important contributions to behavioral ecology, stress physiology and conservation biology. The knowledge acquired in this research should facilitate conservation of African carnivores, and thus contribute to the economic well-being of Kenya, which is intimately linked with revenues from eco-tourism. This research program will also contribute significantly to the professional development of a new generation of global scientists who are united in their desire to understand and protect the natural world.

Technical abstract
The intellectual focus of this project is the behavioral ecology, physiology, and conservation of African carnivores. Mammalian carnivores are critical to the stability and integrity of ecosystems around the world, largely because they play key roles in regulating such important ecosystem processes as interspecific competition and predator-prey dynamics. Despite their importance, however, carnivores are in global decline due to a combination of habitat degradation and direct human persecution. In fact, today many carnivore populations are declining even within protected areas. It has become clear in recent years that our ability to conserve mammalian carnivores, including most of those in Africa, is limited by a dearth of knowledge about many aspects of their basic biology. This international research training program aims to fill these gaps in our knowledge in regard to African carnivores, and to apply that new knowledge to improving carnivore management; this program should thus ultimately facilitate carnivore conservation across the African continent. During the proposed funding period, students will use experimental and observational methods to test hypotheses suggesting 1) relationships among social complexity, foraging demands and general intelligence, 2) endocrine substrates of cooperative behavior, 3) how anthropogenic activities affect the behavior, physiology and demography of mammalian carnivores, and 4) best carnivore management practices. This is the only training program in the United States where both undergraduate and graduate students can obtain field research experience investigating the biology of free-living African carnivores. Most past participants in this program have reported their experiences in Kenya to be life-changing, setting them on trajectories of professional development they otherwise never would have dreamed possible.

Rodent models, studies of captive primates, and data from human populations indicate that early life experiences have long-lasting effects on health, and that early life experiences and longevity often vary with socioeconomic status. This study utilizes existing data and archived biospecimens from a long-term field study of a gregarious mammal with a social structure permitting comparisons among status classes to assess effects of the early social environment on temperament and fitness. Effects of the early environment to be assessed include quality of maternal care, peer interactions and social status. Available data and specimens permit exploration of relationships among the early social environment, mechanisms of gene expression, circulating stress hormones, individual temperament, and longevity. The methods employed include high-throughput next-generation DNA sequencing techniques, bioinformatics and advanced statistical methods. Broader impacts of this work include a deeper understanding of social and molecular determinants of adverse stress phenotypes. Ultimately, characterization of the early life social factors that shape adult stress phenotypes in free-living, gregarious mammals will facilitate generalization of the research findings to other social species, including our own. In addition to supporting the scientific work above, this project will facilitate a workshop series on research methods and data analysis designed specifically for members of the African Graduate Student Association at Michigan State University.

Social experiences early in life have lasting effects on adult temperament and stress phenotype, often through epigenetic modification of genes, and thus patterns of gene expression, that coordinate the hypothalamic-pituitary-adrenal axis. Using data from the MSU Mara Hyena Project, a 28-year study of free-living, gregarious hyenas in Kenya, this proposal will investigate how social factors relate to adverse stress phenotypes, and elucidate the extent to which this relationship is mediated by DNA methylation. Funding from this project will support two research goals. First, this proposal will use Reduced Representation Bisulfite Sequencing (RRBS) to identify differentially methylated regions (DMRs) of the hyena genome that are associated with high vs. low stress phenotypes based on assessment of adult hyena temperament and stress hormones, as well as differences in early social experiences including maternal rank, maternal care, and interactions with clan mates. DMRs that are predictive of the adult stress phenotypes will be identified using Mixed Model Association for Count data via data Augmentation. The second goal is to use mediation analysis to assess whether the identified socially-induced, stress-related epigenetic pathways mediate the effect of early experience on longevity. Findings from this work will improve mechanistic understanding of how social factors affect behavioral and physiological stress phenotypes in an important new animal model. Because a proximate epigenetic mechanism (DNA methylation) is assessed in relation to an ultimate consequence (fitness), this work represents a large step forward in terms of understanding the role of epigenetics in evolution - a concept that has been largely unexplored.