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dc.contributor.authorChardine, John W.en_US
dc.date.accessioned2009-07-09T18:42:43Z
dc.date.available2009-07-09T18:42:43Z
dc.date.issued1978-07-09T18:42:43Z
dc.identifier.urihttp://hdl.handle.net/10464/2041
dc.description.abstractThe reproductive biology of the Ring-billed Gull (Larus delawarensis) was studied on Gull Island, Presqu'ile Provincial Park, Ontario, in 1976 and 1977. Early started clutches (comprising the majority of clutches on Gull Island) in 1977 produced more chicks per nest (2.20 ± 0.09) than late started clutches (0.86 ± 0.13) as a result of reductions in mean clutch size, hatching success and fledging success with date of clutch initiation. Seasonal changes in mean clutch size, hatching success and fledging success also resulted in early clutches, initiated at the peak of clutch starts, producing more chicks per nest (2.34 ± 0.11) than either pre-peak (2.13 ± 0.20) or post-peak (1.82 ± 0.29) clutches. Possible reasons for these trends, including the observed predominance of immature plumaged, breeding gulls in late started areas, are discussed. Clutches were deserted at night for varying lengths of time from at least 15 April until 10 May, 1977. It is suggested that this nocturnal desertion behaviour resulted in the enhancement of inter- and intra-clutch hatching synchrony in early started areas and further, that this may in part explain the existence of the behaviour in terms of its adaptive significance.en_US
dc.language.isoengen_US
dc.publisherBrock Universityen_US
dc.subjectRing-billed gull--Ontario--Gull Island.en_US
dc.subjectRing-billed gull--Reproduction.en_US
dc.subjectVariation (Biology)--Ontario--Gull Island.en_US
dc.subjectSea birds--Ontario--Gull Island.en_US
dc.titleSeasonal variation in the reproductive biology of the ring -billed gull (Larus delawarensis)en_US
dc.typeElectronic Thesis or Dissertationen_US
dc.degree.nameM.Sc. Biological Sciencesen_US
dc.degree.levelMastersen_US
dc.contributor.departmentDepartment of Biological Sciencesen_US
dc.degree.disciplineFaculty of Mathematics and Scienceen_US
refterms.dateFOA2021-08-07T02:26:38Z


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