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dc.contributor.authorBadger, Janelle Jean
dc.date.accessioned2021-12-15T21:25:43Z
dc.date.available2021-12-15T21:25:43Z
dc.date.issued2021-08
dc.identifier.urihttp://hdl.handle.net/11122/12592
dc.descriptionDissertation (Ph.D.) University of Alaska Fairbanks, 2021en_US
dc.description.abstractFitness variation among individuals is a key tenet of eco-evolutionary theory, as natural selection acts upon this variation to bring about evolutionary change. Our understanding of individual heterogeneity and its evolutionary consequences in wild populations is limited, particularly for long-lived animals which are difficult to observe on a biologically relevant scales. This dissertation explores the dynamics of reproductive heterogeneity in a long-lived, iteroparous animal stemming from individual variation, energetic trade-offs, and ecological conditions using over 35 years of longitudinal data on a large sample of marked female grey seals (Halichoerus grypus) breeding on Sable Island, Nova Scotia. Using mixed-effects regression and novel mark- recapture techniques, I investigate three topics. First, I evaluated the evidence for and structure of individual heterogeneity in reproductive performance and determined how this heterogeneity interacts with increasing population size. In particular, I assessed whether population density affects individual-level reproduction, and may alter or amplify differences among individuals. Next, I investigated the relative contributions of individual heterogeneity and energetic trade-offs as drivers of life history variation by exploring the relationship between age-specific reproductive performance and survival. Finally, I determined how physical characteristics in early ontogeny may be a source for individual variation in reproductive success. Overall, I showed that individual heterogeneity is a prevalent and important feature of the Sable Island breeding population that interacts with ecological conditions. Variation among individuals in reproductive ability appears to be a main driver of variation in life history trajectories, and this variation may in part stem from physical characteristics and conditions during early ontogeny. These results have important implications for future demographic and ecological analyses on this population as it reveals that individual variation cannot be ignored to accurately estimate vital rates and underlying individual trade-offs. This work is one of few on long-lived marine mammals and may provide insights into drivers of life history variation of other systems of long-lived, iteroparous animals that are not so well observed.en_US
dc.description.sponsorshipDepartment of Fisheries and Oceans Canada, and Parks Canadaen_US
dc.description.tableofcontentsChapter 1: Introduction of dissertation -- Chapter 2: Variation in individual reproductive performance amplified with population size in a long-lived carnivore -- Chapter 3: Consistent differences among individuals more influential than energetic trade-offs in life history variation in grey seals -- Chapter 4: Reproductive success is influenced by early development: the covariation of natal body size and reproductive performance in grey seals -- Chapter 5: Conclusions of dissertation -- Appendix.en_US
dc.language.isoen_USen_US
dc.subjectGray sealen_US
dc.subjectNova Scotiaen_US
dc.subjectReproductionen_US
dc.subject.otherDoctor of Philosophy in Biological Sciencesen_US
dc.titleDrivers of life history variation in a long-lived, marine predator: individual heterogeneity in reproductive performance of grey seals (Halichoerus grypus)en_US
dc.typeDissertationen_US
dc.type.degreephden_US
dc.identifier.departmentWildlife Biology & Conservation Programen_US
dc.contributor.chairBreed, Greg
dc.contributor.committeeBowen, W. Don
dc.contributor.committeeDoak, Pat
dc.contributor.committeeMueter, Franz
dc.contributor.committeeKitaysky, Alexander
refterms.dateFOA2021-12-15T21:25:43Z


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