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dc.contributor.authorKnowlton, Jessieen_US
dc.contributor.otherDepartment of Ecology and Evolutionen_US
dc.date.accessioned2012-05-17T12:20:54Z
dc.date.available2012-05-17T12:20:54Z
dc.date.issued1-Dec-11en_US
dc.date.submittedDec-10en_US
dc.identifierKnowlton_grad.sunysb_0771E_10382.pdfen_US
dc.identifier.urihttp://hdl.handle.net/1951/56038
dc.description.abstractInteractions between species in groups are often ignored in studies of the effects of anthropogenic change on species' persistence. However, given their global ubiquity, mixed species groups have the potential to be models for community ecology. The purpose of my dissertation was to advance the understanding of the drivers of mixed species flocking behavior in birds, as well as how human disturbance affects these interactions and species' nest survival in a unique and highly threatened landscape in the Tumbesian region of Ecuador. I predicted that interspecific interactions would be disrupted and species would have lower nest survival in vegetation disturbed by small-scale livestock grazing and clearing of trees. Further, I predicted that perceived predation risk would be more important than feeding benefits in explaining flocking behavior. To obtain my results I employed line transect counts, mixed flock observations, foraging observations, vegetation plots, livestock abundance surveys, predatory raptor abundance surveys, arthropod traps, nest searching and monitoring. Based on observations of 431 mixed species flocks, I found habitat disturbance had little impact on these interspecific associations in arid scrub, but that there were large negative impacts in tropical dry forest vegetation. Further, based on observations of 805 nests, the nest survival of most species was more greatly negatively impacted by habitat disturbance in tropical dry forest than in arid scrub vegetation. I also determined that in this region birds are forming mixed flocks primarily to avoid predation rather than to accrue feeding efficiency benefits. However, participants were also able to forage at higher rates when in flocks than when alone or with conspecifics, suggesting that birds gain feeding benefits as a side effect of choosing to be with mixed flocks to avoid predation. My findings highlight the importance of examining multiple factors when attempting to predict species' long term persistence or creating conservation management plans. For example, determining how species richness, abundances, interactions, behavior and reproductive success varied across a landscape consisting of various levels of human disturbance allowed me to gain a more complete picture of species specific and community wide impacts of disturbance in this region.en_US
dc.description.sponsorshipStony Brook University Libraries. SBU Graduate School in Department of Ecology and Evolution. Lawrence Martin (Dean of Graduate School).en_US
dc.formatElectronic Resourceen_US
dc.language.isoen_USen_US
dc.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.en_US
dc.subject.lcshEcologyen_US
dc.subject.otherBehavior, Conservation, Landscape ecology, Mixed species flock, Nest survival, Tumbesian regionen_US
dc.titleEffects of habitat degradation on species interactions and reproductive success in an Ecuadorian bird communityen_US
dc.typeDissertationen_US
dc.description.advisorAdvisor(s): Catherine H. Graham. Committee Member(s): Resit Akcakaya; Lev Ginzburg; Steven C. Latta.en_US
dc.mimetypeApplication/PDFen_US


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