Proposal (893) to South
American Classification Committee
Merge Stymphalornis
into Formicivora
Background: In 1995 Marcos
Bornschein, the late Bianca Reinert, and Dante Martins Teixeira described a new
species of antbird from southern Brazil (Bornschein et al. 1995). At the time
of discovery, this species was represented by only two specimens, an adult
female and an immature male. Bornschein et al. noted a resemblance, both in
general shape (long slender bill, long graduated tail) and plumage between the
new species and some species of Formicivora. On the basis of an
apparently distinctive pattern of syringeal musculature, however, Bornschein et
al. erected a new genus, Stymphalornis, for the new species, acutirostris.
New information: Shortly thereafter,
Luis Gonzaga completed a phylogenetic analysis of Formicivora based on
external morphology, syringeal morphology, vocalizations, and natural history
characters (Gonzaga 2001). Gonzaga made it a point to include Stymphalornis
in this survey. He concluded that Stymphalornis was embedded in Formicivora,
and was most closely related to White-fringed Antwren Formicivora grisea
and Rusty-backed Antwren Formicivora rufa. As a result, when a second
taxon (paludicola), closely related to acutirostris, was
described in 2013, it was described in Formicivora (Buzzetti et al. 2013).
(Note that the co-authors of Buzzetti et al. included both Reinert and
Bornschein, two of the three describers of Stymphalornis.)
Soon
thereafter, Gustavo Bravo published a phylogenetic analysis of antwrens based
on DNA sequence data, from both mitochondrial and nuclear genes (Bravo et al.
2014). Bravo et al. confirmed both that Stymphalornis is embedded in Formicivora
and that it is most closely related to Formicivora grisea and Formicivora
rufa.
Analysis: Multiple lines of
evidence consistently indicate that Stymphalornis is best treated as a
junior synonym of Formicivora. SACC has been aware of this issue at
least since the time it deliberated on whether to recognize paludicola
as a species (comments in AOS-SACC Proposal 693, Recognize Formicivora paludicola as a valid
species), but has not elected to address the question. In
the meantime, other checklists have stayed current with recent advances with
respect to avian taxonomy, and classify acutirostris and paludicola
in Formicivora (Dickinson and Christidis 2014, Piacentini et al. 2015,
del Hoyo and Collar 2016).
Recommendation: I recommend that SACC transfer Stymphalornis acutirostris (including
paludicola) to Formicivora.
Literature Cited:
Bornschein, M. R., B. L. Reinert, and D. M. Teixeira
(1995) Um novo Formicariidae do sul do Brasil (Aves, Passeriformes). Publicação
Técnico-Científica do Instituto Iguaçu de Pesquisa e Preservação Ambiental 1:
1-18, Rio de Janeiro.
Bravo,
G. A., J. V. Remsen Jr., and R. T. Brumfield (2014) Adaptive processes drive
ecomorphological convergent evolution in antwrens (Thamnophilidae). Evolution
68: 2757–2774. https://doi.org/10.1111/evo.12506
Buzzetti,
D. R. C., R. Belmonte-Lopes, B. L. Reinert, L. F. Silveira, and M. R.
Bornschein (2013) A new species of Formicivora Swainson, 1824
(Thamnophilidae) from the state of São Paulo, Brazil. Revista Brasileira de
Ornitologia 21: 269–291. http://www.revbrasilornitol.com.br/BJO/article/view/5409
Dickinson,
E.C., and L. Christidis (2014) The Howard & Moore complete checklist of the
birds of the world. Fourth edition. Volume 2. Aves Press, Eastbourne, United
Kingdom.
Gonzaga, L. P. (2001) Análise filogenética do gênero Formicivora
Swainson, 1825 (Aves: Passeriformes: Thamnophilidae) baseada em caracteres
morfológicos e vocais. PhD dissertation, Universidade Federal do Rio de
Janeiro, Rio de Janeiro. https://pantheon.ufrj.br/bitstream/11422/3518/70/542849.pdf
del
Hoyo, J., and N.J. Collar. 2016. HBW and BirdLife International illustrated
checklist of the birds of the world. Volume 2. Lynx Edicions, Barcelona.
Piacentini,
V. de Q., A. Aleixo, C. E. Agne, G. N. Maurício, J. F. Pacheco, G. A. Bravo, G.
R. R. Brito, L. N. Naka, F. Olmos, S. Posso, L. F. Silveira, G. S. Betini, E.
Carrano, I. Franz, A. C. Lees, L. M. Lima, D. Pioli, F. Schunck, F. Raposo do
Amaral, G. A. Bencke, M. Cohn-Haft, L. F. A. Figueredo, F. C. Straube, and E.
Cesari (2015) Annotated checklist of the birds of Brazil by the Brazilian Ornithological
Records Committee / Lista comentada das aves do Brasil
pelo Comitê Brasileiro de Registros Ornitológicos. Revista Brasileira de
Ornitologia:
90–298. http://revbrasilornitol.com.br/BJO/article/view/1263/pdf_905
Tom Schulenberg,
December 2020
________________________________________________________________________________________________________________________
Comments
from Remsen:
“YES. The genetic data require this merger.”
Comments
from Stiles:
“YES. Transferring this species to Formicivora
is long overdue, given the solid genetic evidence.”
Comments
from Areta:
“YES. A long overdue change! I confess that I adore the name Stymphalornis, but it has to make place
to Formicivora for all the known
reasons.”
Comments
from Jaramillo:
“YES. No comments other than I am saddened to lose Stymphalornis.”
Comments
from Zimmer:
“YES. Multiple data sets (genetic, vocal,
morphological, ecological) strongly support this change.”
Comments from Robbins: “YES, the Bravo et al. molecular data set
make this a straightforward decision of merging Stymphalornis into Formicivora.”
Comments
from Bonaccorso:
“YES. All available evidence supports this change.”
Comments
from Pacheco:
“YES. Approving a widely accepted decision.”