Mitochondrial-DNA Polymorphism in the Oilbird (Steatornis Caripensis, Steatornithidae) in Venezuela

A13sTRAcT.--Mitochondrial-DNA(mtDNA) polymorphisms were studied in the Oilbird (Steatornis caripensis).Twelve closely related (P = 0.06 to 0.35%) mtDNA haplotypes were found in Oilbird colonies studied in northeastern and northwestern Venezuela.Eleven of the mtDNA clones are related to the ancestral one by one or two mutational steps.Femalemediated gene flow is high (Nm > 1) among the colonies studied.As a consequence of the high female-mediated gene flow, no phylogeographic structuring among the mtDNA composite haplotypes was observed.Evidence from mtDNA analysis suggests that Oilbird populations in Venezuela have gone through a bottleneck.Results also seem to indicate that the annual postbreeding migrations of Oilbirds from the Guacharo Cave to the caves in the Mata de Mango area involve mostly the breeding adults, whereas juveniles disperse from the Guacharo Cave to the Mata de Mango cave system for longer periods.