Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross

dc.contributor.advisorRyan, Peteren_ZA
dc.contributor.authorVincent, Zachariah Daviden_ZA
dc.date.accessioned2015-11-08T04:57:52Z
dc.date.available2015-11-08T04:57:52Z
dc.date.issued2008en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractI studied a long-term data set for Wandering Albatrosses Diomedea exulans collected at sub-Antarctic Marion Island to investigate adult survival, breeding biology and factors affecting reproductive success of this long-lived pelagic seabird. Until recently, the complex adult life cycle has caused biases in conventional mark-recapture modelling analyses that assume that recapture probability is equal for 'observable' and 'unobservable' states of the biennial adult life cycle. During 'sabbaticals' taken after successful and late-failed breeding attempts, the chances of resighting an adult Wandering Albatrosses are reduced, thus affecting estimated recapture rates. I applied a multi-state mark-recapture method to the colony breeding data from Marion Island (1987-2005). This method allows individual albatrosses to move through a network of breeding states according to previous breeding history using transition probabilities to estimate survival, breeding and breeding success probability. The best fit models in the multi-state analysis were those representing constant survival and independent breeding probabilities, suggesting that Wandering Albatrosses constrain reproductive investment to ensure long-term survival. I used the parameter estimates in a transition matrix to calculate the steady state equilibrium for the Wandering Albatross breeding population. For the first time I was able to estimate that approximately 3000 pairs of Wandering Albatrosses use Marion Island for nesting. I also describe the effects of age, sex and experience on Wandering Albatross reproductive success. Birds that were most successful began breeding at the mean age of first breeding and older and younger birds were less successful in 5/10 year periods after the onset of breeding. Disappearance from the population decreased with an increase of age of first breeding. I tested the selection and experience hypotheses on birds with 'complete' histories defined according to an imposed rule on recovery data. Males appeared to increase breeding success as a result of selective removal of low-quality individuals from the population (the selection hypothesis), whereas females appeared to improve their breeding success as a result of increased experience.en_ZA
dc.identifier.apacitationVincent, Z. D. (2008). <i>Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross</i>. (Thesis). University of Cape Town ,Faculty of Science ,Percy FitzPatrick Institute of African Ornithology. Retrieved from http://hdl.handle.net/11427/14713en_ZA
dc.identifier.chicagocitationVincent, Zachariah David. <i>"Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross."</i> Thesis., University of Cape Town ,Faculty of Science ,Percy FitzPatrick Institute of African Ornithology, 2008. http://hdl.handle.net/11427/14713en_ZA
dc.identifier.citationVincent, Z. 2008. Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Vincent, Zachariah David AB - I studied a long-term data set for Wandering Albatrosses Diomedea exulans collected at sub-Antarctic Marion Island to investigate adult survival, breeding biology and factors affecting reproductive success of this long-lived pelagic seabird. Until recently, the complex adult life cycle has caused biases in conventional mark-recapture modelling analyses that assume that recapture probability is equal for 'observable' and 'unobservable' states of the biennial adult life cycle. During 'sabbaticals' taken after successful and late-failed breeding attempts, the chances of resighting an adult Wandering Albatrosses are reduced, thus affecting estimated recapture rates. I applied a multi-state mark-recapture method to the colony breeding data from Marion Island (1987-2005). This method allows individual albatrosses to move through a network of breeding states according to previous breeding history using transition probabilities to estimate survival, breeding and breeding success probability. The best fit models in the multi-state analysis were those representing constant survival and independent breeding probabilities, suggesting that Wandering Albatrosses constrain reproductive investment to ensure long-term survival. I used the parameter estimates in a transition matrix to calculate the steady state equilibrium for the Wandering Albatross breeding population. For the first time I was able to estimate that approximately 3000 pairs of Wandering Albatrosses use Marion Island for nesting. I also describe the effects of age, sex and experience on Wandering Albatross reproductive success. Birds that were most successful began breeding at the mean age of first breeding and older and younger birds were less successful in 5/10 year periods after the onset of breeding. Disappearance from the population decreased with an increase of age of first breeding. I tested the selection and experience hypotheses on birds with 'complete' histories defined according to an imposed rule on recovery data. Males appeared to increase breeding success as a result of selective removal of low-quality individuals from the population (the selection hypothesis), whereas females appeared to improve their breeding success as a result of increased experience. DA - 2008 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2008 T1 - Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross TI - Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross UR - http://hdl.handle.net/11427/14713 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/14713
dc.identifier.vancouvercitationVincent ZD. Survival and reproduction in a biennially-breeding seabird : the Wandering Albatross. [Thesis]. University of Cape Town ,Faculty of Science ,Percy FitzPatrick Institute of African Ornithology, 2008 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/14713en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentPercy FitzPatrick Institute of African Ornithologyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherZoologyen_ZA
dc.subject.otherOrnithologyen_ZA
dc.subject.otherDemographyen_ZA
dc.titleSurvival and reproduction in a biennially-breeding seabird : the Wandering Albatrossen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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