Proposal
(123) to South
American Classification Committee
Split Melanerpes
pulcher from M. chrysauchen
Effect on South American
CL: This would elevate a taxon to species rank that that we
treat as a subspecies of a species on our list; it is the only subspecies of
that subspecies in South America.
Background: The
Colombian taxon pulcher was formerly (e.g., Cory 1919)
regarded as a separate species from Melanerpes chrysauchen,
but they were treated as conspecific by Peters (1948). Eisenmann (1955),
however, continued to treat pulcher as a species, and Wetmore
(1968) provided rationale for treating this treatment. However, this
has not been followed by subsequent authors (Meyer de Schauensee 1970, Ridgely
1976, Short 1982, AOU 1983, 1998, Hilty & Brown 1986, Ridgely & Gwynne
1989, Sibley & Monroe 1990, Winkler et al. 1995, Winkler & Christie
2002), except for Stiles & Skutch (1989), who tacitly followed Wetmore
(1968).
Pulcher is
endemic to the Magdalena Valley of n. Colombia; its distribution is disjunct
from that of nominate chrysauchen, which is found from sw. Costa
Rica to w. Panama.
Pulcher differs
from nominate chrysauchen in several aspects of plumage
(from Winkler & Christie 2002): (1) white on mantle is partly barred, (2)
paler forehead patch extends to forecrown, (4) belly more extensively barred,
and (5) male's red crown extends all the way to the nape. The females differ
more; in chrysauchen, the crown is mostly yellowish with a narrow
transverse black band, whereas in pulcher, the forehead is whitish,
most of the crown in black, and the hindcrown is red, with yellowish only on
the nape.
No other differences
(e.g., voice) between the two have been reported as far as I know.
"New"
information: Wetmore (1968) considered pulcher to deserve species
rank; he wrote:
"Peters [1948] and other writers have recently
listed Centurus pulcher (Sclater) of northern Colombia as a
subspecies of chrysauchen, but after careful study this does
not seem warranted. A series of 11 specimens of that bird collected by M. A.
Carriker, Jr., in Antioquia, Bolívar, and Santander, differ in .... [enumeration
of the plumage characters above] . The two are undoubtedly are allied but
differ so definitely, and are so widely separated geographically, that they
appear specifically distinct."
Analysis:
There's not much to analyze. Cory, Eisenmann, Wetmore, and Stiles & Skutch
considered the plumage characters of pulcher sufficiently
different from chrysauchen to merit species rank, whereas
others did not. The former set of authors has an explicit rationale, whereas
the lumpers did not. However, Wetmore did not place his rationale in any sort
of comparative framework, e.g., along the lines of "if allopatric
melanerpine taxa X, Y, and Z are ranked as species, then pulcher also
should be considered a species" or "if parapatric melanerpine taxa X
and Y are not freely interbreeding, and they differ less from each other than
do pulcher and chrysauchen, then ...
."Regardless of which treatment an author followed, I suspect that Wetmore
was really the only one who gave this situation any serious consideration.
Cruising through Winkler
& Christie (2002), I can find at least one example that would support
treating them as conspecific from the comparative standpoint. Melanerpes
aurifrons has strong geographic variation, with some subspecies,
e.g., dubius, having almost entirely red crowns and red bellies
(these are golden or gray except for center of crown in nominate aurifrons);
yet these subspecies evidently intergrade wherever in contact and are thus all
treated as conspecific. More broadly, plumage color and some aspects of pattern
alone don't really seem to be "important" in species limits in
woodpeckers (e.g., Colaptes auratus/cafer in central North America,
Colaptes melanochloros/melanolaimus in South America).
Recommendation: I
don't have a strong recommendation on this one ... I could go either way
depending on others' comments. This proposal was written mainly just to
stimulate discussion of the issue. My inclination is to vote "NO",
given within-species variation in coloration in woodpeckers, until convinced
that a split is the best course.
Literature Cited (partial):
CORY, C.
B. 1919. Catalogue of birds of the Americas. Field Mus. Nat. Hist. Publ., Zool.
Ser., vol. 13, pt. 2, no. 2.
EISENMANN,
E. 1955. The species of Middle American birds. Trans. Linn. Soc. New York 7:
1-128.
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. 1970. A guide to the birds of South America. Livingston
Publishing Co., Wynnewood, Pennsylvania.
PETERS,
J. L. 1948. Check-list of birds of the world, vol. 6. Harvard University Press,
Cambridge, Massachusetts.
RIDGELY
R. S., AND J. A. GWYNNE. 1989. A guide to the birds of Panama, with Costa Rica,
Nicaragua, and Honduras (2nd ed.). Princeton Univ. Press, Princeton, New
Jersey.
SHORT,
L. L., JR. 1982. Woodpeckers of the world. Delaware Museum of Natural History,
Greenville, Delaware.
SIBLEY,
C. G., AND B. L. MONROE, JR. 1990. Distribution and taxonomy of birds of the
World. Yale University Press, New Haven, Connecticut.
STILES,
F. G., AND A. SKUTCH. 1989. A guide to the birds of Costa Rica. Cornell Univ.
Press, Ithaca, New York.
WETMORE,
A. 1968. The birds of the Republic of Panamá, part 2. Smithsonian Misc.
Collect., vol. 150.
WINKLER,
H., AND D. A. CHRISTIE. 2002. Family Picidae (woodpeckers. Pp. 296-558 in "Handbook
of the Birds of the World, Vol. 7. Jacamars to woodpeckers." (J. del Hoyo
et al., eds.). Lynx Edicions, Barcelona.
WINKLER,
H., D. A. CHRISTIE, AND D. NURNEY. 1995. Woodpeckers. Houghton Mifflin, Boston.
Van
Remsen, April 2004
Voting chart for SACC proposals
100-218
Comments from Stiles:
"[YES] another tough one, though I have experience with both forms
involved. The plumage differences are of a magnitude that could go either way.
Behaviorally, ecologically and vocally (to my ear) chrysauchen and
pulcher are extremely similar if not identical but then again, so is pucherani (which
nobody has suggested lumping), and it is not so vastly different in plumage.
The ranges of pucherani and pulcher must approach very closely in
N Colombia but I am unaware of any specific site where they have both been
reported, and know of no reported hybrids. In birds of CR, I accepted Wetmore’s
split simply because I knew of no other reasonably detailed analysis (and still
don’t) and because of my ignorance of pulcher. My (weak)
inclination would be to consider pucherani, chrysauchen and pulcher allospecies
of a superspecies, but I am aware that the superspecies category has been
considerably abused in woodpeckers by Short (and the AOU). For instance, rubricapillus and hoffmanni
are placed in different superspecies but hybridize massively where they come
into contact (since the 1980,s) in SW Costa Rica I mentioned this, including
specimens, in the CR guide to no avail, but didn’t publish anything more
specific because at that time I was moving to Colombia and a student (who then
disappeared) was interested in doing a thesis on same. So here I am, on the
fence, with a tendency to vote Yes but a willingness to change if cogent
contrary evidence were to appear."
Comments from Robbins:
"I have no strong opinion on this one. Like Van and Gary, I could go
either way."
Comments from Jaramillo:
"YES. Not a strong opinion here,
similar to other members that have voted thus far. Woodpeckers are a difficult
bunch, with some good species differing mainly in size and call, but not
plumage, while others differ in plumage and not voice, and with many taxa that
hybridize or intergrade. It is a mess. The influence of Lester Short in
woodpecker taxonomy has been good and bad, I think that his application of the
biological species concept appears to have been very rigid and conservative,
and hides much of the complexity that is actually present within this
family."
Comments from Nores: "SI. Yo primeramente había escrito que No, pero aclarando
que pensaba firmemente que podría ser una especie distinta, tan válida con M.
pucherani y M. chrysauchen. Después de leer el
comentario de Stiles voto que Sí."
Comments from Silva:
"YES. My decision is based on Gary's comments."
Comments from Zimmer:
"I vote "YES". I'm not overwhelmed by the plumage distinctions,
but these, coupled with the range disjunction and the well-established pattern
of endemism in the Chiriquí region of SW Costa Rica and W Panama leads me to
believe that we are talking about separate species. Gary's experience with both
forms (I'm familiar only with chrysauchen) carries a lot of weight
with me."
Comments from Stotz:
"NO. While in many respects this case resembles the previous two
woodpecker splits, it differs in being in a genus with pretty extensive
morphological variation with and among species. In terms of plumage, pulcher doesn't
seem all that different (although I have to admit that pucherani isn't
either), and there are no obvious vocal differences. In the absence of any
serious evidence to support a split of this species (even unpublished), I have
to vote no."
Comments from Pacheco: "[SIM] Eu concordo com os argumentos de Stiles e
considero uma boa medida, até razões em contrário, manter pulcher em
separado de chrysauchen."
Additional comments from
Robbins: "YES. As I mentioned earlier, I could go either way
with this one. But, to move things along, I'll vote "yes" to
recognize Melanerpes pulcher as a species."