Proposal
(744) to South American Classification Committee
Transfer White-lined Antbird from Percnostola to Myrmoborus
Effect on SACC: This proposal would transfer the White-lined Antbird (Percnostola lophotes) to Myrmoborus.
Background and analysis: Percnostola lophotes
was described by Hellmayr and Seilern (1914) from specimens collected by
Watkins in Puno, Peru. Both sexes were described. Later, Berlioz (1966)
described a male thamnophilid collected in Madre de Dios, Peru, as Percnostola macrolopha. Parker (1982)
mist-netted a mated pair of thamnophilids (and later collected a series) in
Madre de Deus and found that the male was "nearly identical" to the
male described by Berlioz and that the male described by Hellmayr and Seilern
"agrees closely with female-plumaged specimens, with the exception of the
blackish primary coverts of their bird, a characteristic of male lophotes," and thus presumably a
subadult male. Parker then provided the first natural history information for
the species. He noted that in vocalizations and behavior P. lophotes was "quite unlike" its supposed congeners,
and he suggested there were similarities with Thamnophilus, Sakesphorus
and Myrmeciza species. Since then, in
discussion and publications (e.g., Zimmer and Isler 2003) field ornithologists
have expressed doubt regarding the generic placement of P. lophotes, but a supported recommendation for its generic
placement was never advanced.
In a study aimed to test the monophyly
of the genus Myrmeciza, a framework
of DNA-based phylogenetic relationships was prepared incorporating Myrmeciza species and their closest
relatives including Percnostola and Myrmoborus species (Isler et al. 2013).
Maximum-likelihood and Bayesian analysis produced similar typologies indicating
with high support that P. lophotes
was imbedded in a subclade consisting of Myrmoborus
species and was sister to M. melanurus.
This was at first a surprise (this placement had never to our knowledge had
been suggested in the literature) but then became a "why hadn't we seen
this” when the phylogeny was overlaid with morphological and behavioral
characters (see Zimmer and Isler 2003, Isler et al 2013). Putting aside the
crested look of P. lophotes, its
plumage resemblance to M. melanurus
is obvious, a similarity never been mentioned in the literature perhaps because
of the limited and disconnected ranges of the two species. Morphometric
proportions of bill and tail, which helped direct Hellmayr to place lophotes in Percnostola, are similar between Percnostola and Myrmoborus
species so they are of no consequence in the shift. The lowland,
near-river-edge habitat preferences of P.
lophotes (with bamboo) and M.
melanurus are generally similar and differ from the typically upland, often
sandy-soil, habitats of Percnostola
species. The domed nest of P. lophotes,
placed in bamboo debris on the ground closely resembles the nest of M. leucophrys (Lebbin et al. 2007).
Domed nests of Percnostola species
are similar, although sometimes placed slightly above the ground.
Recommendation: We recommend a "YES" with regard to recognizing Myrmoborus lophotes.
References:
Berlioz, J. 1966. Descriptions
de deux espèces nouvelles d'oiseaux du Pérou. L'Oiseau et la Revue Française
d'Ornithologie 36:1–3.
Hellmayr, C.E., and J. G. von
Seilern. 1914. Neue Vögel aus dem tropischen Amerika. Verhandlungen der
Ornithologischer Gesellschaft in Bayern 12:87–92.
Isler,
M. L., G. A. Bravo, and R. T. Brumfield. 2013. Taxonomic revision of Myrmeciza
(Aves: Passeriformes: Thamnophilidae) into 12 genera based on phylogenetic,
morphological, behavioral, and ecological data. Zootaxa 3717 (4): 469–497.
Lebbin,
D. J., P. A. Hosner, M. J. Andersen, U. Valdez, and W. P. Tori. 2007. First
description of nest and eggs of the White-lined antbird (Percnostola lophotes), and breeding observations of poorly known
birds inhabiting Guadua bamboo in
southeastern Peru. Boletín SAO 16:119–132.
Parker,
T. A., III. 1982. Observations of some unusual rainforest and marsh birds in
southeastern Peru. Wilson Bulletin 94:477–493.
Zimmer,
K. J., and M. L. Isler. 2003. Family Thamnophilidae (typical antbirds). Pages
448–681 in Handbook of the Birds of the World. Volume 8: Broadbills to
Tapaculos (J. del Hoyo, A. Elliot, and D. A. Christie, Editors). Lynx Edicions,
Barcelona, Spain.
Morton
L. Isler, Gustavo A. Bravo, & Robb T. Brumfield, March 2017
___________________________________________________________
Comments
from Remsen:
“YES. Solid genetic data. Interesting case of phenotypic similarities
to congeners overwhelmed by one prominent feature on the head.”
Comments
from Jaramillo:
“YES. This would make a nice article for
the general birding public to illustrate how some obvious morphological
features on a bird can mask equally obvious non-visual information and cloud
the understanding of relationships in birds. It is an interesting story. But
cutting to the chase, yes, it is clear that this species needs to be
transferred to Myrmoborus.”
Comments from Zimmer: “YES.
Plumage, structure, habitat, nest architecture, vocalizations, and (if
memory serves me) even stereotypical tail movements all conform with what the
genetic evidence suggests.”
Comments
from Areta:
"YES. Clear genetic evidence supports this move and is further supported
by plumage and natural history data."
Comments
from Stiles:
"YES. Genetic and plumage data
(except the crest) are sufficient for this transfer."
Comments
from Robbins:
"Yes, the genetic data leave no doubt that lophotes should be transferred to Myrmoborus."
Comments from Pacheco: "YES. Although not previously suspected, there is clear support
of genetic and morphological data for this transfer."
Comments from Claramunt: "YES. The data are robust,
and the solution simple."