Forpus modestus has priority over Forpus sclateri
Proposal (458) to South American Classification Committee
Effect on South American CL: change scientific name from Forpus sclateri (Dusky-billed Parrotlet) to Forpus modestus due to validation of an earlier name of what had been seen as the junior subspecies.
Peters (1937) used Forpus sclateri (Gray, 1859, type from the río Javari, Peru) as the oldest available name for Dusky-billed Parrotlet. James L. Peters also introduced the name F. s. eidos as a nomen novum for Psittacula modesta (Cabanis, 1848, type from British Guiana), which he considered a secondary junior homonym of Psittacula modesta (Fraser, 1845).
Fraser’s name applies to the Long-tailed Parakeet Psittacula longicauda modesta, of Enggano Island, Sumatra, and Cabanis’ modesta to the genus Forpus, Boie, 1858. Thus, these authors independently applied the name modesta to different nominal genera (Psittacula Cuvier, 1800 [type: Psittacus alexandri Linnaeus] and Psittacula Illiger, 1811 [type: Psittacus passerinus Linnaeus]), obviating homonymy.
Because Cabanis’ name has been employed as valid since 1899 (e.g. Ihering & Ihering 1907, Snethlage 1914, Cory 1918, Naumburg 1930, Pinto 1938), Forpus modestus must be considered the valid name for Dusky-billed Parrotlet, with sclateri as a subspecies and eidos a synonym.
A review published in the subsequent number of the bulletin (B.B.O.C 126(3): 254) by a Chairman of the Standing Committee on Ornithological Nomenclature (SCON) of the International Ornithological Committee (IOC) gave the following opinion:
“These authors proposed that Forpus sclateri eidos Peters, 1937, be replaced by the name modestus Cabanis, 1848. This case has been a subject of discussion within the SCON and, whilst Pacheco & Whitney are correct in their assertion, the supporting Article 57.8.1 of the ICZN Code, which states ‘Homonymy between identical species-group names in combination (originally or subsequently) with homonymous generic names having the same spelling but established for different nominal genera* (Art. 53.2) is to be disregarded’, was not cited in explanation. Authors of such papers will, in future, be expected to include reference to the specific articles in the Code that apply to the case at hand and support their conclusions.”
(*) The co-existence of two identically spelled generic names (with different authors and different types); within one phylum is, of course, extremely rare.
Recommendation: We recommend a "YES" vote on accepting this proposal.
Cory, C. B. 1918. Catalogue of birds of the Americas and the adjacent islands. Field Mus. Nat. Hist., Zool. Ser. 13, pt. 2(1): 1–315.
Ihering, H. & Ihering, R. 1907. Catálogos da Fauna brazileira, vol. 1. Museu Paulista, São Paulo.
Naumburg, E. M. B. 1930. The birds of Matto Grosso, Brazil. Bull. Amer. Mus. Nat. Hist. 60: 1–432.
Pacheco, J. F. e B. M. Whitney. 2006. Mandatory changes for the scientific names of three Neotropical birds. Bull. Brit. Orn. Cl. 126(3): 242-244.
Peters, J. L. 1937. Check-list of birds of the world, vol. 3. Harvard Univ. Press, Cambridge, MA.
Pinto, O. M. O. 1938. Catálogo das aves do Brasil e lista dos exemplares que as representam no Museu Paulista, 1a. parte. Rev. Mus. Paulista 22: 1–556.
Snethlage, E. 1914. Catálogo das aves amazônicas contendo todas as especies descriptas e mencionadas até 1913. Bol. Mus. Para. Emilio Goeldi 8: 1–465.
José Fernando Pacheco & Edward Dickinson, August 2010
Comments from Stiles: “YES, again to go along with ICZN.”
Comments from Nores: “YES. When Cabanis described the Peruvian bird in 1849 as Psittacula modesta, the name was not valid because it there was used previously by Fraser in1845. However, when it was determined that the Peruvian bird did not belong to Psittacula if not to Forpus, the name became valid, because any bird has the name Forpus modestus.”