1,721,048 research outputs found
Low rank and primiparity increase fecal glucocorticoid metabolites across gestation in wild geladas
No full texthttp://dx.doi.org/10.13039/100005966 Leakey Foundationhttp://dx.doi.org/10.13039/100007259 Stony Brook Universityhttp://dx.doi.org/10.13039/100006363 National Geographic Societyhttp://dx.doi.org/10.13039/100007270 University of Michiganhttp://dx.doi.org/10.13039/100000001 National Science Foundatio
Dorothy L. Cheney (1950-2018). Primatologist who gave voice to animal communication and cognition
No full textIntergroup encounters in Honduran mantled howler monkeys (Alouatta palliata)
Get PDFHonors (Bachelor's)Evolutionary AnthropologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/98885/1/megcole.pd
Where do you stand? Research shows clues in rules of the wild
No full textIf you wonder where you stand in the social pecking order at work, home and in the community, a little known group of primates found only in the highlands of Ethiopia may offer some clues. Video interview with Jacinta Beehner and Thorn Bergmanhttp://deepblue.lib.umich.edu/bitstream/2027.42/93325/1/gelada.mp
Support for the Challenge Hypothesis in wild, adult male chacma baboons (Papio ursinus).
No full textHonors (Bachelor's)"Brain, Behavior, and Cognitive Sciences"Anthropology and PsychologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/77634/1/shaylib.pd
Maternal Stress Effects Across Primate and Non-Primate Models
No full textHonors (Bachelor's)Evolutionary AnthropologyUniversity of Michiganhttps://deepblue.lib.umich.edu/bitstream/2027.42/139610/1/emasood.pd
The importance of underground foods in female gelada (Theropithecus gelada) socioecology
Get PDFFood plays a foundational role in animals’ lives, particularly during periods of food scarcity. Foods consumed only during times of food scarcity, “fallback foods”, exert strong
selective forces in shaping behavior and life history. However, the role of fallback foods has not been examined in many species. Geladas (Theropithecus gelada) present a particular conundrum. While geladas primarily eat grasses blades, alternative diet items, such as underground plant storage organs, are a large part of the diet, especially in the dry season, when green grasses are scarce. In this thesis, I investigate the role that these alternative diet items have in gelada foraging and behavioral ecology in a population of wild geladas in the Simien Mountains National Park, Ethiopia, from January, 2015 - January, 2016.
I asked the following questions: (1) How much of the gelada diet (across seasons) is comprised of grass? And, (2) to what extent do geladas utilize “fallback foods”? I quantified monthly diet profiles of adult geladas from eight study units (n=37 females, 17 males) using instantaneous scan samples (n=7,533 feeding scans), and seasonal above- and underground food availability. I compiled data from published gelada feeding studies and compare the relative importance of underground foods in the gelada diet. Geladas preferred green grasses year-round (up to 93.4% of monthly foraging time), but spent a large amount of time consuming underground foods in the dry season (up to 58% of monthly foraging time). Grass consumption was positively correlated with grass availability, and underground food consumption was negatively correlated with green grass availability. In contrast with grasses, underground food availability did not vary seasonally, which supports the hypothesis that underground foods are important fallback foods for geladas.
Next, I examined the role that underground foods play in shaping gelada social relationships among females. Socioecological models predict that female competition should increase when food resources are clumped and defensible. Female geladas thus represent a puzzle for socioecology; they feed on dispersed resources that cannot be monopolized, yet they exhibit aggressive competition and a strict dominance hierarchy. I hypothesized that female geladas must routinely contest underground resources during times of scarcity. To test this hypothesis, I used behavioral data from adult females (n=32 females; 1,424 observation hours) collected in the dry and wet seasons to assess the effect of behavioral context, season, and on the probability of receiving aggression. I found that females were more likely to receive aggression from within-unit females than from females outside of their unit, that aggression was highest during the dry season when geladas were not feeding on a widely-dispersed resource (grass) but rather were feeding on underground foods, that aggression was higher during a feeding context than a non-feeding context, and even more so when the feeding was on underground food items, and that low-ranking females were the most likely to receive aggression in these contexts. Therefore, the results of this study support the hypothesis that female aggression (and the dominance hierarchy that ensues) functions to usurp lower-ranking females from their underground excavations that expose valuable underground foods. These excavations represent an investment of time, energy, and a level of uncertainty as to whether the effort will uncover a valuable food resource, all of which can be eliminated or reduced for a high-ranking individual that can acquire the “patch” without investing any of the effort. In sum, the results presented here support the hypothesis that fallback foods can be contestable resources, and can be influential in shaping social relationships among female geladas.Master of Science (MS)Natural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/134702/4/Jarvey_Julie_Thesis.pd
Social correlates of androgen levels and dispersal age in juvenile male geladas
No full texthttp://dx.doi.org/10.13039/100007270 University of Michiganhttp://dx.doi.org/10.13039/100000001 National Science Foundationhttp://dx.doi.org/10.13039/100005966 Leakey Foundatio
FACIAL RECOGNITION: INTRASPECIFIC VARIATION AND DEVELOPMENT OF SPECIALIZATION IN POLISTES FUSCATUS, A MODEL SYSTEM
Get PDFSpecialized face learning, the ability to learn and remember faces better than other
visual stimuli, occurs across a wide range of social animal taxa. However, the ontogeny
of specialized face learning, specifically whether it develops due to innate, learned, or a
combination of innate and learned factors, remains debated in the literature. Empirical
data on face specialization has supported all three hypotheses, yet conflicting methodologies and data interpretations complicate our understanding of the ontogeny of
face specialization. In this study, we use Polistes fuscatus (paper wasp), a system with
intraspecific variation in developmental environment (innate) and experience (learned), to test the ontogeny of specialized face learning. Our results support the combination
hypothesis for the development of specialized face learning, with both innate and learned factors needed to fully explain intraspecific variation in face specialization. Wasps with better early nutritional environment (gynes) learned to discriminate faces more accurately than wasps with poorer nutrition during early development (workers), perhaps due to innate variation in neural structures. Furthermore, older wasps (foundresses) learned faces faster than other stimuli, while younger wasps (gynes) showed no difference in rate of learning between stimuli. We posit that older wasps have greater specialization for learning faces than younger wasps due to higher levels of facial exposure throughout life. Controlled manipulations of early development and adult experience will be useful to provide a more detailed analysis of the ontogeny of specialized face learning. Our results, which suggest that the combined effects of learned and innate factors are necessary to explain the ontogeny of specialized face learning, may be generalizable to all social animals. In many signaling systems, intraspecific variation in recognition abilities is based on developmental stage, experience, or caste. However, the occurrence of intraspecific variation in recognition has not been thoroughly examined in species with individual recognition. For example, previous work has shown that individual recognition is an important aspect of the social life of Polistes fuscatus (paper wasp) nest founding queens, as individual recognition stabilizes dominance interactions and reduces aggression. Yet, to date the potential for individual recognition among P. fuscatus workers has been largely ignored. Here, we explore whether there is intraspecific variation in individual recognition by testing P. fuscatus worker recognition abilities in a series of staged contests. The results indicate that P. fuscatus workers are capable of individual recognition: focal workers paired with previously encountered partners experienced significantly less aggression and more nonaggressive bodily contact than focal workers paired with unknown social partners. Therefore, this study finds no evidence of intraspecific variation in individual recognition across castes of P. fuscatus. We propose two potential explanations for individual recognition among workers: 1) worker individual recognition may be favored because it provides social benefits to workers, or 2) worker individual recognition may be a byproduct of selection for individual recognition in foundresses. Individual recognition is often considered a cognitively challenging form of recognition, so future studies that compare the sophistication of recognition across castes will be useful to assess whether there are more subtle differences in cognitive abilities or recognition behavior between P. fuscatus nestfounding queens and workers.Master of Science (MS)Ecology and Evolutionary Biology Traditional Masters ProgramUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/98097/1/Injaian MS Thesis FINAL (1).pd
- …
