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. Henicorhina 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 was
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 northwestern 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.
_______________________________________________________________________________________________
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."