Proposal (#236) to South American Classification Committee
Change linear sequence of
Henicorhina species
Proposal:
Henicorhina species currently recognised by SACC are listed
in the following sequence:
Henicorhina leucosticta White-breasted Wood-Wren
Henicorhina leucophrys Gray-breasted Wood-Wren
Henicorhina negreti Munchique Wood-Wren
Henicorhina leucoptera Bar-winged Wood-Wren
Henicorhina includes two widespread and well-known species
groups: lowland H. leucosticta and highland H. leucophrys.
H. leucoptera and H. negreti are each (relatively)
recently described (Fitzpatrick et al. 1977; Salaman et al. 2003)
and both were thought related to H. leucophrys taxa at
the time of their description.
A recent molecular (mtDNA) phylogeny published by Dingle et al.
(2006) did not include samples of H. negreti but held H.
leucoptera to be more closely related to H. leucosticta
inornata than H. leucophrys. This would mandate a change
in the SACC's linear sequence to move leucoptera next to
leucosticta. In Salaman et al. (2003), we presented morphological
and biogeographical evidence supporting the hypothesis that H.
negreti is more closely related to nominate H. leucophrys
than any other taxon. This species should therefore stay where
it is in the absence of evidence of closer relationships to other
taxa.
Moving leucoptera up, as proposed, produces the following
linear sequence:
Henicorhina leucosticta White-breasted Wood-Wren
Henicorhina leucoptera Bar-winged Wood-Wren
Henicorhina leucophrys Gray-breasted Wood-Wren
Henicorhina negreti Munchique Wood-Wren
Discussion: Dingle et al. (2006) and Mann et al. (2006)'s
phylogenies are each consistent with two well-supported sister
clades existing in Henicorhina (i) for H. leucosticta
taxa (which Dingle et al. show to include H. leucoptera);
and (ii) for H. leucophrys taxa (which would presumably
include H. negreti). Following a ruling on Proposal 219,
Mann et al. (2006)'s phylogeny may mandate a change in the sequence
of the genera Thryothorus, Henicorhina and Cyphorhinus.
However, even if such steps were taken, this would not require
any up-ending of this proposed sequence for Henicorhina.
The proposed sequence above would minimise change within the genus
Henicorhina whether the genus were placed before or after
Thryothorus or Cyphorhinus - it "makes sense"
in the context of the Dingle et al. phylogeny reading top to bottom
or bottom to top.
There are likely to be various splits to current Henicorhina
species in the future. Dingle et al. (2006) suggested splitting
H. leucosticta into at least three taxa: (i) a Central
American prostheleuca group; (ii) a Chocó inornata
group; and (iii) an Amazonian leucosticta group. Such propositions
lack published vocal or morphological analysis in support and
material in north-western Colombia where the inornata and
prostheleuca groups come closest together was not sequenced.
However, Dingle et al.'s proposed splits nonetheless appear to
have very strong molecular support. Winker et al. (1996) further
suggested that some taxa in Dingle et al.'s prostheleuca
group could also be split (and the race dariensis, presumably
part of this group, ranges into northern Colombia thus is SACC
relevant). Finally, in Salaman et al. (2003), evidence was presented
that H. leucophrys (as currently constituted) may require
to be split in the long term due to parapatry or sympatry of various
vocally and morphologically distinctive forms in Colombia apparently
without hybridisation (e.g. brunneiceps / nominate leucophrys
in the West Andes and bangsi / anachoreta in Santa
Marta. Dingle et al. (2006) also demonstrated that various distinct
lineages exist within H. leucophrys. The linear re-arrangement
in this proposal is therefore just a preliminary step towards
a better arrangement for Henicorhina. If Dingle et al.
(2006)'s splits were followed, the taxa H. prostheleuca
and H. inornata would need inserting after H. leucosticta
but with no disruption necessary to the new sequence above.
Conclusion: To confirm, this proposal is just to change
the linear sequence (move H. leucoptera to above H.
leucophrys), not for any of the splits discussed above. I
would recommend a YES vote.
References are all on SACC references site.
Thomas Donegan, August 2006.
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Comments from Stiles: "YES. The proposal seems logical, reasonably noncontroversial and involving only a minor change in the list in any case, so YES."
Comments from Jaramillo: "YES - Appears to be a well supported and sensible small change."
Comments from Pacheco: "YES. A alteração sugerida na sequência é muito bem corroborada."