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Diagnoses of hybrid hummingbirds ( Aves : Trochiiidae ) . 5 . Probable hybrid origin of Amazilia distans Wetmore &
| Content Provider | Semantic Scholar |
|---|---|
| Author | Phelps Graves, Gary R. |
| Copyright Year | 2011 |
| Abstract | —Amazilia distans Wei more & Phelps, 1956, is believed to be a hybrid between Hylocharis eyamts and Amazilia fimbriata. The hybrid, collected in Estado Tachira. Venezuela, exhibits a blended mosaic of plumage characters of the parental species. External measurements of the hybrid fall between the character means; of the parental species which overlap in size. The unique holotype of Amazilia distans Wetmore & Phelps, 1956 was collected by Ramon Urbano at "El Salao" (300 m) near Burgua, Estado Tachira, Venezuela, on 17 July 1954. Originally deposited in the Coleccidn Omitologica Phelps (No. 60790). Caracas, the type was cataloged on 9 October 1956, in the National Museum of Natural History (USNM 461695), Smithsonian Institution. Collar et al.'s (1992) report of a second specimen in the Coleccion Phelps was based on a misreading of the Phelps card catalog (fide M. Lentino, N. Collar). References treat A. distans as a valid species (e.g.. Morony et al. 1975, Meyer de Schauensee & Phelps 1978, Hilly & Brown 1986. Sibley & Monroe 1990, Collar et al. 1992). Analyses reported here suggest that it represents a hybrid between Hylocharis cyanns and Amazilia fimbriata. I provide a detailed hybrid diagnosis employing the methods and assumptions outlined in Graves (1990) and Graves & Zusi (1990). Materials and Methods The holotype of Amazilia distans was sexed as male (testes drawn on original label). The unstriated maxillary ramphotheca (see Ortiz-Crespo 1972) and brilliant plumage of the specimen indicate that it is an adult in definitive plumage (Pigs. 1, 2). The unique appearance of A. distans cannot be attributed to mutation or developmental variation of any known taxon. Nor does it seem to represent a morphologically distinctive or geographically isolated population of another species of Amazilia. Consequently, A. distans appears either to be a valid species or a hybrid. As hybrids have no standing in zoological nomenclature, the burden of proof lies with the taxonomist to reject conclusively the hybrid origin of A. distans before bestowing species status on it. I was unable to reject I he hypothesis of hybridity. Hybridization between species from different subfamilies, Phaethornithinae and Trochilinae. is unknown (Graves 1990). Assuming a hybrid origin for A. distans, the pool of potential parental species ( = geographic pool) can be limited to the species of trochiline hummingbirds (« — 23; see Appendix 1) that occur regularly below 1000 m elevation in the region immediately south and east of the Andes in Estado Tachira and Estado A pure. Venezuela (Phelps & Phelps 1958, Meyer de Schauensee & Phelps 1978. Hilty & Brown 1986). 1 compared A. distans directly with specimens of all hummingbird species in the collections of the National Museum of Natural History. Smithsonian Institution, paying particular attention to those listed in Appendix 1. Notes, photographs, and videotape of the holotype were compared with the extensive VOLUME III. NUMBER I 29 table I.—Ranges and means (± one standard ileviation) of measurements (mm) of representative specimens i.i.liilr male) of Hylm-harix cyanus, Amazitutfimlustiiii, and the Hybrid, Hylwhans cvanus x Amazilia fiinhriaia i= Amazilia distorts Wctmore & Phelps. 1956: USNM 461695). in = I*) fi'tih mil*! Hybrid Win^ ehord 47.1-53.0 52.4-56.5 51 0 49.8 ±15 54.7 t 1.4 Bill length 14.8-18.5 17,3-22.0 IS,6 16.9 ± I.I 19,8 ± 1.3 Reetrix 1 24.1-27.4 26.2-30.1 26.6 25.9 i 1.2 28.8 ± 1.0 Reetrix 5 25.1-28.1 27.7-32.5 27.4 26.7 ± 1.0 30.6 ± 1.4 •Colombia |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://repository.si.edu/bitstream/handle/10088/12853/vz_Graves_1998_PBSW_hummerhybrid_5.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
