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Title:Social, ecological, and developmental influences on fruit and invertebrate foraging strategies and gut microbial communities in white-faced capuchins (Cebus capucinus)
Author(s):Mallott, Elizabeth K
Director of Research:Garber, Paul A.
Doctoral Committee Chair(s):Garber, Paul A.
Doctoral Committee Member(s):Malhi, Ripan S.; Stumpf, Rebecca M.; MacKinnon, Katherine C.
Department / Program:Anthropology
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):white-faced capuchins
foraging ecology
DNA metabarcoding
gut microbiome
Abstract:Primates are challenged by spatiotemporal variation in resource availability, and a central question in biological anthropology is how primates compensate for seasonal variation in food resources by adjusting their foraging strategies. How primates respond to variation in invertebrate availability has rarely been the focus of studies of primate foraging ecology. This dissertation examines the role of insectivory in shaping foraging strategies, elucidates developmental differences in invertebrate foraging strategies, and investigates the role of the gut microbiome in mediating dietary changes in white-faced capuchins. White-faced capuchins (Cebus capucinus) are an instructive model for examining the influences of changes in both fruit and arthropod availability on foraging strategies, as they devote a mean of 44.4% of feeding and foraging time to fruit, 38.0% to invertebrates, and 1.2% to vertebrates. A group of 20-22 white-faced capuchins was studied from January 2013 through January 2014 at La Suerte Biological Field Station in northeastern Costa Rica. Data was collected from individually recognizable adult and juvenile capuchins on diet (fruit, invertebrates, leaves, seeds, vertebrates, other), activity budget (feeding, foraging, traveling, resting, social, other), affiliative and agonistic interactions, nearest neighbor identity and distance, foraging subgroup size and spread, and geographic location at 2-minute intervals during 1-hour focal follows. Crown volume, diameter at breast height, number of food items in the crown, and average mass of five food items was collected for each tree in which the group fed for more than four minutes in order to assess patch productivity. Every two weeks, fruit resource availability was tracked using 25 100x4 meter phenology transects, and invertebrate resource availability was assessed using 10 composite insect traps and sweep net sites. Fecal samples were collected throughout the study period (n=225). DNA was extracted from fecal samples, and the COI mtDNA and the v3-v5 region of the 16S rRNA genes were amplified and sequenced to identify invertebrates consumed and the gut microbial community structure. The second chapter uses social network analysis to quantify group-level responses of white-faced capuchins to changes in food availability. The results indicate that increases in fruit abundance and decreases in patch density increase group cohesion (network density = 0.48±0.01 during periods of high abundance and patch density, network density = 0.40±0.07 during periods of low abundance and patch density), indicating that individuals may be decreasing group cohesion as fruit resources become less available in order to avoid feeding competition. Additionally, the abundance and distribution of invertebrate resources does not have a consistent effect on group cohesion, and the results suggest that capuchins do not see invertebrates as a uniform resource. In the third chapter of my dissertation, innovative molecular methods are used to identify the taxa of invertebrates present in the diet of white-faced capuchins and more closely investigates how animal prey foraging strategies are influenced by invertebrate availability, and the role of ontogeny on the development of foraging skills in capuchins. This chapter compares frequency with which DNA sequences assigned to specific Orders and Families of invertebrates are found in adult and juvenile feces, showing that juvenile capuchins are eating embedded, concealed, and highly mobile invertebrates, such as Gryllidae and Cercopidae, less often when compared with adults. Additionally, the results indicate that white-faced capuchins are consuming a greater diversity of arthropod prey than other New World monkey species, with the exception of squirrel monkeys, with 29 Orders, 90 Families, and 287 genera of invertebrates identified in their diet. Finally, chapter four examines how changes in fruit and invertebrate foraging behavior and dietary choice influence gut microbial community structure and function in white-faced capuchins. This chapter shows that the relative abundance of several microbial genera have significant relationships with the minutes per hour spent feeding and foraging on several fruit species and invertebrate Families. In addition, these same fruit and invertebrate taxa have significant relationships with the relative abundance of predicted microbial metabolic functional pathways in the gut. This dissertation presents a multi-level approach to studying white-faced capuchin foraging ecology, and the findings underscore the importance of looking beyond food abundance and distribution as the primary factors driving nonhuman primate foraging strategies. The results suggest that models of primate foraging strategies should include not only ecological and social information, but also individual-level factors such as physiology, personality, genetic traits, and commensal microbial relationships. The integrative multifaceted approach to primate foraging ecology in this dissertation provides a framework with which to begin to truly understand the complexity and plasticity of primate foraging strategies.
Issue Date:2016-06-17
Rights Information:Copyright 2016 Elizabeth Mallott
Date Available in IDEALS:2016-11-10
Date Deposited:2016-08

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