Variation and population structure of the tourmaline sunangel, Heliangelus exortis exortis (Aves, Trochilidae). American Museum novitates ; no. 2811

Abstract

"The nominate form of the polytypic Andean hummingbird the tourmaline sunangel, Heliangelus exortis exortis, exhibits dramatic variation in a female polychromatism of throat iridescence within and among populations that has not heretofore been appreciated. An analysis of the geographic population structure of samples referable to H. e. exortis was conducted to determine the biological status and historical process of differentiation of polychromatically differentiated samples. Geographic variation in additional color and six mensural characters is discordant within and between the sexes. The polychromatism shows both regular and mosaic patterns of geographic variation. Geographic patterns of variability in the polychromatism do not appear to result from increased variability in putative zones of hybridization between differentiated populations. No character breaks that might indicate noninterbreeding parapatric forms were noted. It is concluded that H. e. exortis comprises a single biological entity and taxon within the polytypic H. exortis complex. The evolutionary origins of the complex pattern of geographic variation in H. e. exortis are discussed. I suggest that biological attributes, in addition to potential geographic barriers, are necessary for a full understanding of the geographic differentiation seen in H. e. exortis"--P. [1].