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dc.contributor.advisorGarland, Ellen C.
dc.contributor.advisorRendell, Luke
dc.contributor.advisorCarroll, Emma Louise
dc.contributor.advisorGarrigue, Claire
dc.contributor.authorEichenberger, Franca
dc.description.abstractHow the underlying forces of sexual selection impact reproductive tactics including elaborate acoustic displays in cetaceans remains poorly understood. Here, I combined 26 years (1995-2020) of photo-identification, behavioural, (epi)genetic, and endocrine data from an endangered population of humpback whales (New Caledonia), to explore male reproductive success, age, physiology, and population dynamics over almost a third of the lifespan of a humpback whale. First, I conducted a paternity analysis on 177 known mother-offspring pairs and confirmed previous findings of low variation in reproductive success in male humpback whales. Second, epigenetic age estimates of 485 males revealed a left-skewed population age structure in the first half of the study period that became more balanced in the second half. Further, older males (> 23 years) more often engaged in certain reproductive tactics (singing and escorting) and were more successful in siring offspring once the population age structure stabilised, suggesting reproductive tactics and reproductive success in male humpback whales may be age-dependent. Third, using enzyme immunoassays on 457 blubber samples, I observed a seasonal decline in male testosterone in the population over the breeding season. Testosterone levels appeared highest during puberty, then decreased and levelled off at the onset of maturity, yet were highly variable at any point during the breeding season and across males of all ages. Lastly, I investigated the influence of genetic diversity at the major histocompatibility complex (MHC) class I and class IIa (DQB and DRB-a) on patterns of male reproductive success in humpback whales. Mating pairs shared fewer alleles than expected under random mating at MHC class I and IIa, thus, providing evidence of an MHC-mediated female mate choice in humpback whales. This thesis provides novel, critical insights into the evolutionary consequences of commercial whaling on the demography, patterns of reproduction and sexual selection of exploited populations of baleen whales.en_US
dc.description.sponsorship"This work was supported by a University of St Andrews School of Biology Ph.D. Scholarship and the Louis M. Herman Research Scholarship 2022 to Franca Eichenberger. Sample collection and analyses from 2018-2020 were supported by grants to Ellen C. Garland (Royal Society University Research Fellowship (UF160081 & URF\R\221020), Royal Society Research Fellows Enhancement Award (RGF\EA\180213), Royal Society Research Grants for Research Fellows 2018 (RGF\R1\181014), National Geographic Grant (#NGS-50654R-18), Carnegie Trust Research Incentive Grant (RIG007772), British Ecological Society Small Research Grant (SR18/1288) and School of Biology Research Committee funding)."--Fundingen
dc.subjectReproductive successen_US
dc.subjectBaleen whalesen_US
dc.subjectSexual selectionen_US
dc.subjectPopulation recoveryen_US
dc.subjectEpigenetic ageingen_US
dc.subjectGametic-mark recaptureen_US
dc.subjectMate choiceen_US
dc.subjectPopulation age structureen_US
dc.subject.lcshHumpback whale--Reproductionen
dc.subject.lcshHumpback whale--Endocrinologyen
dc.subject.lcshSexual selection in animalsen
dc.subject.lcshCourtship in animalsen
dc.titleUnravelling the complex reproductive tactics of male humpback whales : an integrative analysis of paternity, age, testosterone, and genetic diversityen_US
dc.contributor.sponsorUniversity of St Andrews. School of Biologyen_US
dc.contributor.sponsorLouis M. Herman Research Scholarshipen_US
dc.contributor.sponsorRoyal Society (Great Britain)en_US
dc.contributor.sponsorNational Geographic Societyen_US
dc.contributor.sponsorCarnegie Trust for the Universities of Scotlanden_US
dc.contributor.sponsorBritish Ecological Societyen_US
dc.type.qualificationnamePhD Doctor of Philosophyen_US
dc.publisher.institutionThe University of St Andrewsen_US
dc.publisher.departmentUniversity of Auckland. French Institute for Research on Sustainable Development (IRD)en_US

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