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dc.contributor.authorFlores De Gracia, Eric Enrique
dc.date.accessioned2013-04-08T14:07:35Z
dc.date.issued2012-11-12
dc.description.abstractThe causes and consequences of variation in aposematic signals during immature stages are not clearly understood. This thesis explores the effects of early environment on the expression of aposematic signals in the green and black poison frog (Dendrobates auratus), and the consequences of variation in such components in the wild. It also explores how aposematic expression relates to levels of chemical defences in immature froglets. Embryos and larvae of poison frogs in the genus Dendrobates are known to be darkly pigmented. This thesis reports for the first time polymorphism in egg pigmentation in D. auratus and ontogenetic colour change through development reverting to a normally pigmented phenotype; however whether this pigmentation results from constraints or has adaptive consequences remains unclear. Evidence on how immature individuals allocate resources to growth and warning signalling is scarce. Experimental results in this thesis show that food supply during early environment affected body size and signal luminance in post-metamorphic froglets. Therefore the relative importance of these traits in relation to predation risk was further tested, using artificial prey in a field experiment. The results indicated that rates of attack by birds correlated negatively with body size, and on the contrary survival of artificial prey was independent of signal luminance. I therefore tested the hypothesis that in the wild larger, relatively well-nourished juvenile frogs are chemically better defended. I found that in fact larger juveniles are at a selective advantage conferred by their greater foraging efficiency and their superior levels of chemical defences. Overall, these results shows plasticity in aposematic traits in relation to early environmental nutrition in D. auratus; and suggests that acquiring large body size and similar integument colour as to adults are key determinants for survival during the early stages of their terrestrial life.en_GB
dc.description.sponsorshipIFARHU-SENACYTen_GB
dc.identifier.grantnumberNo. 270-2009-167en_GB
dc.identifier.urihttp://hdl.handle.net/10871/8170
dc.language.isoenen_GB
dc.publisherUniversity of Exeteren_GB
dc.rights.embargoreasonSome chapters are still under review for publication.en_GB
dc.subjectaposematismen_GB
dc.subjectDendrobates auratusen_GB
dc.subjectearly developmenten_GB
dc.subjectplasticityen_GB
dc.titleEarly development and the honesty of aposematic signals in a poison frogen_GB
dc.typeThesis or dissertationen_GB
dc.date.available2013-11-30T04:00:09Z
dc.contributor.advisorBlount, Jonathan
dc.descriptionDoctoral scholarship program 2005-2010en_GB
dc.publisher.departmentBiosciencesen_GB
dc.type.degreetitlePhD in Biological Sciencesen_GB
dc.type.qualificationlevelDoctoralen_GB
dc.type.qualificationnamePhDen_GB


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