Genetic Diversity and Population Structure of Reddish Egrets along the Texas Coast

摘要

Little is known about tire ecology and population structure of the Reddish Egret (Egretta rufescens). Furthermore, the effects of the near extirpation on genetic variation of Reddish Egrets are unknown. A 223-base-pair region of the mitochondrial DNA (mtDNA) control region was sequenced in 149 Reddish Egret samples from sixteen breeding colonies along the Texas Coast to investigate genetic diversity and population structure. Despite experiencing a severe reduction in population size, Reddish Egrets retained a moderate amount of haplotype (0.705) and nucleotide diversity (0.005). A mismatch distribution among haplotypes and non-equilibrium relationship between the number and similarity of haplotypes (Fu's Fs) are consistent with historical population size changes. No evidence of genetic structuring was found among either colonies or color morphs. Reddish Egrets along tire Texas Coast. appear to form a single panmictic population. The results of this first conservation genetic study of Reddish Egrets serve as a foundation for management and additional research. Received 2 September 2008, accepted 16 February 2009.