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COSTS AND BENEFITS OF COOPERATIVE INFANT CARE IN WILD GOLDEN LION TAMARINS (LEONTOPITHECUS ROSALIA)

dc.contributor.advisorDietz, James M.en_US
dc.contributor.authorSiani, Jennifer Marieen_US
dc.date.accessioned2009-10-06T06:28:41Z
dc.date.available2009-10-06T06:28:41Z
dc.date.issued2009en_US
dc.identifier.urihttp://hdl.handle.net/1903/9615
dc.description.abstractIn cooperative breeding species, nonbreeding individuals typically delay dispersal, forego reproduction and provide care to infants that are not their own. All caregivers must therefore balance infant demands against their own self-interests. In this dissertation I investigate the costs and benefits of cooperative infant care in wild golden lion tamarins <italic> (Leontopithecus rosalia) </italic>. In chapter 1, I examine what factors influence the distribution of infant care to clarify why helpers contribute care to infants. I find that reproductive status strongly influences infant caretaking patterns, with parents contributing significantly more infant carrying and food provisioning than helpers. Parental dominance in caretaking and the lack of variation in infant carrying or food transfers with caregiver age, sex or condition suggests that genetic relatedness dictates these caretaking decisions, with infant behavior also influencing food provisioning. In chapter 2, I investigate the effects of gestation and infant care on activity budgets and body mass to determine if infant care results in detectable short-term costs to caretakers. Tamarins are hypothesized to require assistance from nonreproductive helpers in raising offspring due to ecological (e.g. predation risk, foraging) and energetic costs of gestation and care of infants, usually twins. During gestation, reproductive females do not make behavioral changes that suggest an energy conservation strategy; however, all caregivers make behavioral changes while carrying infants to increase predator awareness and decrease energetic expenditure and are able to maintain a stable body mass throughout infant care. Cooperative infant carrying may allow individuals to balance energetic demands and mitigate predation risk, thus supporting the hypothesis that energetic costs have driven the evolution of cooperative caretaking. In chapter 3, I present the results of an acoustic playback experiment to determine the frequency and intensity of caregiver responses to infant begging vocalizations. Caregiver responses were influenced by reproductive status, sex, condition, experience, group size and activity level, but not familiarity or genetic relatedness. The variation in caregiver responses to infant vocalizations suggests that these responses are flexible and dynamic, shifting with changes in group composition and context and with individual reproductive status and physical condition.en_US
dc.format.extent866680 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.titleCOSTS AND BENEFITS OF COOPERATIVE INFANT CARE IN WILD GOLDEN LION TAMARINS (LEONTOPITHECUS ROSALIA)en_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentBehavior, Ecology, Evolution and Systematicsen_US
dc.subject.pqcontrolledBiology, Zoologyen_US
dc.subject.pqcontrolledBiology, Ecologyen_US
dc.subject.pqcontrolledAnthropology, Physicalen_US
dc.subject.pquncontrolledCooperative breedingen_US
dc.subject.pquncontrolledEnergetic constraintsen_US
dc.subject.pquncontrolledInfant careen_US
dc.subject.pquncontrolledPlayback experimentsen_US
dc.subject.pquncontrolledReproductionen_US
dc.subject.pquncontrolledVocalizationsen_US


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