Proposal (68) to South American Classification Committee
Treat Basileuterus chlorophrys as separate species from B. chrysogaster
Effect on South American CL: This
proposal would split our Basileuterus
chrysogaster into two species,
with recognition of northern chlorophrys as a separate species.
Background: The bird
we treat as one species, Basileuterus
chrysogaster (Golden-bellied
Warbler), has a disjunct distribution, with the subspecies chlorophrys in the Western Andes from central Colombia
to central Ecuador, and the other in the Eastern Andes from central to southern
Peru. This follows the traditional classification (e.g., Hellmayr 1935, Meyer
de Schauensee 1966, 1970, Lowery & Monroe 1968, Meyer de Schauensee &
Phelps 1978, Hilty & Brown 1986, Ridgely & Tudor 1989, Curson et al.
1994, Sibley & Monroe 1990).
The subspecies chlorophrys is very similar in plumage to nominate chrysogaster, differing
primarily in having a mostly olive, not yellow, superciliary, with the yellow
restricted to anterior-most portion.
New information: Ridgely
& Greenfield (2001) treated chlorophrys as a separate species, with the note
that its song is "utterly different" from nominate chrysogaster.
The qualitative description of the song is "a very thin , wiry, buzzy 't-t-t-t-tzzzzzzzzzzzzz" (same
description as in Ridgely & Tudor 1989). However, I can't find a published
description of the song of nominate chrysogaster.
(I'm sure it exists on one or more published CDs and perhaps in published
literature.)
Analysis: The
plumage differences between chlorophrys and chrysogaster are less, in many cases far less, than those between many taxa
currently treated as same subspecies in Basileuterus.
The vocal differences are more weakly documented than in previous parulid
proposals in which vocal differences were part of the argument. I'm sure that
Bob and others are right about the degree of difference between chlorophrys and chrysogaster,
but without formal published documentation, sonograms, etc., I cannot evaluate
the evidence.
Recommendation: I vote
"NO" on this proposal. A published, quantitative analysis of
differences in song is what I need to be convinced on this one.
Literature Cited:
CURSON, J., D. QUINN, AND D.
BEADLE. 1994. Warblers of the Americas. Houghton Mifflin.
HELLMAYR, C. E. 1935. Catalogue of
birds of the Americas. Field Mus. Nat. Hist. Publ., Zool. Ser., vol. 13., pt.
8.
HILTY, S. L., AND W. L. BROWN.
1986. A guide to the birds of Colombia. Princeton University Press, Princeton,
New Jersey.
LOWERY, G. H., JR., AND B. L.
MONROE, JR. 1968. Family Parulidae. Pp. 3-93 in "Check-list of birds of
the World, Vol. 14" (Paynter R. A., Jr., ed.). Museum of Comparative
Zoology, Cambridge, Massachusetts.
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. Vol. II. Field guide. Cornell
University Press, Ithaca, New York.
RIDGELY, R. S., AND G. TUDOR. 1989.
The birds of South America, vol. 1. Univ. Texas Press, Austin.
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, October 2003
________________________________________________________________________________________
Comments from Stotz: "No.
May be inconsistent with my vote on the restarts, but the vocal descriptions
are weaker and the biogeographic pattern is not as distinctive."
Comments from Jaramillo: "NO --
need more data, particularly published data."
Comments from Zimmer: "I
vote "NO", for same reasons outlined in previous proposal."
Comments from Stiles: "NO
for the same reasons [as in Prop 67]."
Comments from Nores: "NO.
Por las mismas razones que la propuesta # 67."