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-oó-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 morfológicas yo aceptaría 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."