Proposal (105) to South American Classification Committee

 

Recognize Geotrygon purpurata as a separate species from G. saphirina

 

Effect on South American CL: This proposal would split our Geotrygon saphirina into two species, with recognition of Trans-Andean purpurata as a separate species.

 

Background: The bird we treat as one species, Geotrygon saphirina (Sapphire Quail-Dove), has three subspecies: (1) trans-Andean purpurata in the Western Andes from central Colombia to northern Ecuador; (2) cis-Andean nominate saphirina on the Amazonian slope of the Eastern Andes and hilly areas of western Amazonia; and (3) (perhaps doubtfully diagnosable?) rothschildii of the Marcapata Valley in Peru. This is the traditional classification (e.g., Meyer de Schauensee 1966, 1970, Goodwin 1983, Hilty & Brown 1986, Sibley & Monroe 1990, Baptista et al. 1997).

 

The trans-Andean population differs primarily (as illustrated in Ridgely & Greenfield 2001) in having a darker, bluer crown; in Baptista et al. (1997), it is also shown as lacking a white wing spot, and having a darker, redder iris, but these differences are not shown or mentioned in Ridgely & Greenfield (2001).

 

New information: Ridgely & Greenfield (2001) treated purpurata as a separate species, with the following note:

 

"G. purpurata is regarded as a species distinct from cis-Andean G. saphirina (Sapphire Quail-Dove), based on several striking plumage differences and its disjunct range."

 

In the field guide volume, Ridgely & Greenfield (2001) gave the voice of saphirina as "Relatively high-pitched (for a dove) song a distinctive quavering 'k-whohh ... k-whohh ... k-whohh ... "' with pause of about 3 seconds between calls." For purpurata, they stated: "Song (in Colombia) described as a soft, hollow 'whoot, whoo-o—-oit,' weak and repeated at short intervals (Hilty & Brown 1986).

 

The split was followed by Gibbs et al. (2001).

 

Analysis: Without direct comparison of specimens, I can't make any statements concerning whether the differences between these two are above or below the levels associated with taxa recognized as species in Geotrygon, but given that no previous author seems to have treated purpurata at the species level, I suspect that the differences are not dramatic. The qualitative descriptions of their voices obviously are intriguing, but Ridgely & Greenfield (2001) did not mention them in their justification, presumably with admirable caution until such differences can be studied.

 

Recommendation: I vote "NO" on this proposal. Several other similar "splits" that have been accompanied by qualitative vocal descriptions and some plumage differences have generally been rejected by SACC, and so I won't repeat here the arguments associated with those proposals. What I would require, minimally, for a "YES" vote is a published analysis of presumed homologous vocalizations from multiple localities within the range of each.

 

Partial Literature Cited:

BAPTISTA, L. F., P. W. TRAIL, AND H. M. HORBLIT. 1997. Family Columbidae (pigeons and doves). Pp. 60-243 in "Handbook of the Birds of the World, Vol. 4. Sandgrouse to cuckoos." (J. del Hoyo et al., eds.). Lynx Edicions, Barcelona.

GIBBS, D., E. BARNES, AND J. COX. 2001. Pigeons and doves. Yale University Press, New Haven.

GOODWIN, D. 1983. Pigeons and doves of the world, 3rd ed. Cornell Univ. Press, Ithaca, New York.

HILTY, S. L., AND W. L. BROWN. 1986. A guide to the birds of Colombia. Princeton University Press, Princeton, New Jersey.

MEYER DE SCHAUENSEE, R. 1966. The species of birds of South America and their distribution. Livingston Publishing Co., Narberth, Pennsylvania.

MEYER DE SCHAUENSEE, R. 1970. A guide to the birds of South America. Livingston Publishing Co., Wynnewood, Pennsylvania.

RIDGELY , R. S., AND P. J. GREENFIELD. 2001. The birds of Ecuador. Cornell University Press, Ithaca, New York.

SIBLEY, C. G., AND B. L. MONROE, JR. 1990. Distribution and taxonomy of birds of the World. Yale University Press, New Haven, Connecticut.

 

Van Remsen, March 2004

 

 

 

Comments from Robbins: "I vote "NO" on this proposal despite the fact that these undoubtedly deserve species status (based on my field experience with both in Ecuador). Saphirina is quite distinct from purpurata from a plumage standpoint and if I recall correctly there is also a size difference (purpurata is larger than saphirina; specimens at ANSP). Ridgely and Greenfield's description of saphirina's voice is correct and I presume Hilty's description of purpurata also is correct. Nonetheless, someone should write this up in a note."

 

Comments from Stiles: "NO. We have specimens of both and the differences are definite but not all that striking. (Given the overall conservatism of plumage in the Columbidae, I am not especially impressed with its value in taxonomic decisions either for or against species status). The vocalizations would be much better evidence, but at the least decent recordings should be made: comparing verbal descriptions, especially by different observers, is doubly subjective. So, NO at least until good recordings are made (how many individuals, etc. will depend upon how different they are, at least in part: if the difference is a quantitative one between generally similar calls/songs, much more detailed sampling and playback expts. will be required than if the differences were to be striking and immediately apparent.)"

 

Comments from Nores: "NO, aunque la diferencia en voces parece importante. De ser real esta diferencia sumado a las diferencias morfol—gicas yo aceptar’a considerarla especie separada, pero por el momento prefiero no innovar."

 

Comments from Jaramillo: "NO _ Voice information needs to be published somewhere."

 

Comments from Zimmer: " NO. Based on described vocal differences, it seems likely that the two taxa do represent good biological species. However, lacking any published analysis, I'd have to pass on this split for the time being."