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Profile - Robert O'Malley
Robert O’Malley
Contact Information
E-mail: romalley@usc.edu
Mail Code: 0371
Started at USC: Fall 2004
Education:
2004 – present
Graduate Student, Integrative & Evolutionary Biology (Biological Sciences)
University of Southern California, Los Angeles
2002
M.A., Anthropology
Thesis: “Variability in foraging and food processing techniques among white-faced capuchins (Cebus capucinus) in Santa Rosa National Park, Costa Rica.”
University of Alberta, Edmonton
1999
B.A., Anthropology & Zoology
Miami University, Oxford
Faculty Advisor(s):
Dr. Craig Stanford, Anthropology
http://www.usc.edu/dept/elab/anth/FacultyPages/stanford.html
Collaborations:
Dr. Linda Fedigan, University of Calgary
Dr. William C. McGrew, University of Cambridge
Research Topics: primatology, wild chimpanzees
Research Description:
My dissertation research will address the question “what factors influence patterns of predation on insects by chimpanzees at Gombe National Park, Tanzania?" through nutritional analyses of insect prey, ecological surveys to assess insect prey availability, density, and predation by chimpanzees, and behavioral observation of chimpanzee insectivory in Gombe National Park, Tanzania.
Chimpanzees (Pan troglodytes) along with bonobos (Pan paniscus) are the closest living relation to modern Homo sapiens, and it has been hypothesized that the last common ancestor of Homo and Pan was similar to a modern chimpanzee.�� Chimpanzees are widely recognized as a useful model for understanding the behavioral ecology of extinct hominids. ��Studies of chimpanzee behavior have previously helped to generate or refine hypotheses about hominid nesting sites, tool use, and the origins of hominid bipedality.�� Studies of the diet and foraging activities of modern chimpanzees have also provided valuable insights into the possible diet and foraging patterns of extinct hominids.
Research on chimpanzee insectivory is important because despite a long-standing emphasis on meat-eating in models of human evolution, there has been relatively little research on the evolutionary significance of other forms of faunivory by hominids.�� Insect-eating is widespread in modern human populations and humans preferentially consume the same five orders of insects favored by most nonhuman primates.�� Unlike other African apes but like modern humans, many populations of chimpanzees habitually make and use tools to prey upon eusocial insects such as honeybees, termites and ants.�� Different chimpanzee communities and populations exhibit cultural variation in prey choice and feeding techniques.�� Also unlike most other primates, chimpanzees and human foragers often show robust sex differences in patterns of animal predation.�� Females of both species typically target small, slow-moving or sedentary prey such as invertebrates or small vertebrates.�� Males typically hunt larger and more mobile vertebrate prey more often than females.�� Some aspects of chimpanzee insectivory, such as patterns of tool-use, have been studied for decades in many populations.�� However, basic information such as the nutritional value of insect foods, the diversity and abundance of insect prey, and data on intra-population differences in insectivory frequency and skill level is often incomplete or absent even from long-term field sites.
This study seeks to test several basic but untested hypotheses about chimpanzee insectivory.�� The first hypothesis is that chimpanzees prefer prey of high energetic and nutritional value.�� Chimpanzees are predicted to prefer species and castes with high caloric and fat content.�� The second hypothesis is that chimpanzees prefer prey species that are encountered frequently and predictably.�� Chimpanzees are predicted to feed more often on social insect species whose colonies occur at high densities.�� The third hypothesis is that chimpanzees prefer prey that yield high energetic returns for the foraging time invested.�� Chimpanzees are predicted to engage in longer and more frequent insectivory bouts during daily and seasonal time periods when foraging returns are highest, and at specific colonies that yield high returns.�� The fourth hypothesis is that adult female chimpanzees are more efficient at tool-assisted insectivory than adult males.�� Females are predicted to engage in longer and more frequent bouts of insectivory, and also demonstrate greater efficiency in termite-fishing and ant-dipping.
I conducted a pilot study at Gombe from February to April of 2008.�� Focal observations began on 13 adult chimpanzees in August 2008 and continued through January 2009.�� These data are currently being entered into databases for analyses.�� Data collection via video recording focused on social insect predation.�� All videotaped sessions will be digitized and analyzed using Noldus Observer software to determine bout length and prey intake rates, as well as to identify variation in techniques for tool manufacture and use. When social insect structures such as termite mounds, ant nests, or bee nests were preyed upon, the inhabitant species, physical characteristics, and location (including GPS coordinates) of the colonies were recorded.�� Insect samples were also collected for nutritional analyses.
I returned to the US from Gombe National Park in January 2009.�� I am now entering my behavioral data into spreadsheets and digitizing the video data I collected.�� In April and May of 2009 I will analyze the samples of insect prey collected in the field to determine nutritional value at the Nutrition Laboratory of the National Zoological Park in Washington, D.C., with the assistance of Dr. Michael Power.�� In September 2009 I will return to Gombe for a second 5-month field season to resume behavioral observation.�� A set of plots will also be established and surveyed to assess the density of termite, ant, and bee colonies in different habitats throughout the park.
The role of meat-eating in hominid evolution has been a topic of considerable scientific interest.�� Insectivory has received relatively less attention, despite archaeological evidence for tool-assisted predation on termites by hominids and the importance of insects as food for many modern human populations.�� This study of insectivory by wild chimpanzees will provide insights into nutritional, ecological, and behavioral factors that are likely to have influenced the foraging activities of extinct hominids.
Recent Publications:
Stanford, C. & O’Malley R.C.�� Sleeping tree choice by Bwindi chimpanzees.��American Journal of Primatology, 70(7): 642-649.
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