Background:The Hair-crested Drongo(Dicrurus hottentottus) exhibits a unique nest-dismantling behavior after the fledging of the young.One hypothesis explaining this behavior is dismantling one's own nest may reduc...Background:The Hair-crested Drongo(Dicrurus hottentottus) exhibits a unique nest-dismantling behavior after the fledging of the young.One hypothesis explaining this behavior is dismantling one's own nest may reduce potential competition for nest sites in the following breeding season because suitable breeding habitat might be limited,and sites are often reused.Methods:By comparing the habitat features at nest and random locations,we determined the nest habitat preference of the Hair-crested Drongo within Dongzhai National Nature Reserve,Henan,China.We also compared habitat features with nesting success to determine if any trends could be detected.Results:We found that nest tree height,diameter at breast height,live crown ratio,tree rank,and presence of overstory were significantly higher at nesting locations than random locations;slope,leaf litter cover percentage and depth,presence of understory and midstory,and number of trees per hectare were significantly lower at nest sites than random sites.Drongos preferred to use some tree species,such as Metasequoia glyptostroboides,Castanea mollissima,and Pterocarya stenoptera for nesting.Failed nests were often associated with habitat with higher percentage of leaf litter on the ground.Conclusion:Our data support that selection of nest sites does occur for this species at this site and therefore support the hypothesis that breeding habitat limitation could be one of the driving forces for the development of the nestdismantling behavior in this species.展开更多
Models of allopatric speciation within an island biogeographic framework suggest that the division of ancestral mainland populations leads to one or more allopatric island species predominantly through natural and sex...Models of allopatric speciation within an island biogeographic framework suggest that the division of ancestral mainland populations leads to one or more allopatric island species predominantly through natural and sexual selection or genetic drift.Here we studied phenotypic divergence in a phylogenetic framework in the Dicrurus paradiseus allospecies complex in Sri Lanka,a continental island located in the Indian plate,to understand the complexity of phenotypic divergence on an island.Members of the genus Dicrurus are known as drongos and are conserved in morphology and plumage,but highly variable in vocalization due to vocal learning and mimicry.Two closely related drongos are found in Sri Lanka:the endemic D.lophorinus(or D.paradiseus lophorinus to many authors)found in the wet zone of the island and the widespread continental species D.paradiseus,which inhabits the dry zone.Sampling from all major populations,and voucher specimens from museums across their range in Sri Lanka,we examined phenotypic and genetic variation in this group.The phenotype showed two clusters:birds with a fish-like tail and erect crest(D.lophorinus),and birds with elongated tail streamers with backwardly curved crest(D.paradiseus).There was no significant difference in the vocal traits compared.The genetic variation was examined using two nuclear(Myo 2 and c-mos)and two mitochondrial(ND2 and Cytb)loci and the phylogenetic relationship was analyzed using the Bayesian inference coalescent-based species tree estimation method.The quantitative criteria for species delimitation provided a score sufficient to consider these two taxa as distinct species by considering measurements of body and plumage,acoustics,behaviour and distribution.The phylogeny supports distinct species status for the Sri Lanka Drongo(Dicrurus lophorinus)and that the D.lophorinus and D.paradiseus sister pair diverged since 1.35 mya.The variation in the crest and the tail plumage(components of phenotype)were the main contributors of the divergence,despite the similarity in general appearance and vocalization of the allopatric species.展开更多
基金support by Dongzhai National Nature Reserve for conducting this studyFunding and support was provided by National Science Foundation East Asia Pacific Summer Institute (EAPSI)+2 种基金Chinese Ministry of Science and TechnologyChina Science and Technology Exchange Center Further funding and support was provided by Alabama A&M University and Beijing Normal University
文摘Background:The Hair-crested Drongo(Dicrurus hottentottus) exhibits a unique nest-dismantling behavior after the fledging of the young.One hypothesis explaining this behavior is dismantling one's own nest may reduce potential competition for nest sites in the following breeding season because suitable breeding habitat might be limited,and sites are often reused.Methods:By comparing the habitat features at nest and random locations,we determined the nest habitat preference of the Hair-crested Drongo within Dongzhai National Nature Reserve,Henan,China.We also compared habitat features with nesting success to determine if any trends could be detected.Results:We found that nest tree height,diameter at breast height,live crown ratio,tree rank,and presence of overstory were significantly higher at nesting locations than random locations;slope,leaf litter cover percentage and depth,presence of understory and midstory,and number of trees per hectare were significantly lower at nest sites than random sites.Drongos preferred to use some tree species,such as Metasequoia glyptostroboides,Castanea mollissima,and Pterocarya stenoptera for nesting.Failed nests were often associated with habitat with higher percentage of leaf litter on the ground.Conclusion:Our data support that selection of nest sites does occur for this species at this site and therefore support the hypothesis that breeding habitat limitation could be one of the driving forces for the development of the nestdismantling behavior in this species.
基金This study was funded by the Collaborative Research Grants of the University of Colombo(to SS)the Special Talent Recruitment grant from Guangxi University(to EG)The fieldwork was conducted with the permission of WL/3/2/19/13(Department of Wildlife Conservation,Sri Lanka)and R&E/RES/NFSRC/2013-01-P-02(Forest Department,Sri Lanka)。
文摘Models of allopatric speciation within an island biogeographic framework suggest that the division of ancestral mainland populations leads to one or more allopatric island species predominantly through natural and sexual selection or genetic drift.Here we studied phenotypic divergence in a phylogenetic framework in the Dicrurus paradiseus allospecies complex in Sri Lanka,a continental island located in the Indian plate,to understand the complexity of phenotypic divergence on an island.Members of the genus Dicrurus are known as drongos and are conserved in morphology and plumage,but highly variable in vocalization due to vocal learning and mimicry.Two closely related drongos are found in Sri Lanka:the endemic D.lophorinus(or D.paradiseus lophorinus to many authors)found in the wet zone of the island and the widespread continental species D.paradiseus,which inhabits the dry zone.Sampling from all major populations,and voucher specimens from museums across their range in Sri Lanka,we examined phenotypic and genetic variation in this group.The phenotype showed two clusters:birds with a fish-like tail and erect crest(D.lophorinus),and birds with elongated tail streamers with backwardly curved crest(D.paradiseus).There was no significant difference in the vocal traits compared.The genetic variation was examined using two nuclear(Myo 2 and c-mos)and two mitochondrial(ND2 and Cytb)loci and the phylogenetic relationship was analyzed using the Bayesian inference coalescent-based species tree estimation method.The quantitative criteria for species delimitation provided a score sufficient to consider these two taxa as distinct species by considering measurements of body and plumage,acoustics,behaviour and distribution.The phylogeny supports distinct species status for the Sri Lanka Drongo(Dicrurus lophorinus)and that the D.lophorinus and D.paradiseus sister pair diverged since 1.35 mya.The variation in the crest and the tail plumage(components of phenotype)were the main contributors of the divergence,despite the similarity in general appearance and vocalization of the allopatric species.
