Proposal (812) to South American
Classification Committee
Split Sierran Elaenia (Elaenia pallatangae) into two species
Part A: Recognize Elaenia olivina as a separate species
Background: Sierran Elaenia, as recognized by SACC,
is a polytypic species, with three subspecies in the Andes (pallatangae, intensa, and exsul) and two in the tepuis (olivina
and davidwillardi).
As one would expect, these were considered to be separate species by early
authors (e.g., Sclater 1888, Hellmayr 1927). Hellmayr (1927), however, also
considered olivina to be “ nearly
allied to” (i.e., closely related to) pallatangae,
and suggested that it was “most probably a geographic race of E. pallatangae”. Zimmer (1941) argued
that the differences between the Andean and tepui groups were bridged by
individual variation, and merged olivina
into pallatangae (davidwillardi of course not having been described yet); this remained the
taxonomy for all subsequent authors until recently.
New information: Frank Rheindt and
colleagues have spent the past decade investigating the phylogenetic
relationships of Elaenia,
using phylogenetic analysis of DNA sequence data, from both mitochondrial and
nuclear genes. A consistent result has been the discovery that both Sierran
Elaenia and White-crested Elaenia (Elaenia
albiceps) are polyphyletic (Rheindt et al. 2008, 2009, Tang et al. 2018).
Andean E. pallatangae are sister to
(and, indeed, extremely similar to) Elaenia
albiceps chilensis, a migratory taxon that breeds south of the range of
Sierran Elaenia. The Roraiman populations of E. pallatangae, on the other hand, belong to a clade made up of Elaenia frantzii (Mountain Elaenia), Elaenia albiceps (northern taxa), Elaenia fallax (Greater Antillean
Elaenia), and Elaenia martinica
(Caribbean Elaenia).
Recommendation: The genetic evidence
indicates that the Andean and tepui groups of Sierran Elaenia are not sister
taxa, and so strongly supports recognizing the olivina group (olivina
and davidwillardi)
was a separate species. I recommend a Yes vote to split olivina and davidwillardi from the pallatangae group.
Part B: If Part A is accepted, then the question of
English names comes up. I recommend Tepui Elaenia for Elaenia olivina. This name accurately describes its range, and
already is in use by Dickinson and Christidis (2014), del Hoyo and Collar
(2016), and the World Bird List. As usual, no fair
voting “no” on this unless a better name is proposed.
Part C: As for Elaenia
pallatangae sensu stricto, this is a case in which the geographic disparity
in the ranges of the two daughter species is great enough that I would be
comfortable with retaining the name Sierran Elaenia. This has been the approach
adopted as well by Dickinson and Christidis (2014), del Hoyo and Collar (2016),
and the World Bird List. Again, no votes
against retaining Sierran unless a better name is proposed.
Literature cited:
Dickinson,
E.C., and L. Christidis (editors). 2014. The Howard and Moore complete
checklist of the birds of the world. Fourth edition. Volume 2. Passerines. Aves
Press, Eastbourne, United Kingdom.
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.
Hellmayr,
C.E. 1927. Catalogue of birds of
the Americas. Part V.
Field Museum of Natural History Zoological Series volume 13,
part 5.
Rheindt, F.E., L. Christidis, and
J.A. Norman. 2008. Habitat shifts in the evolutionary history of a Neotropical
flycatcher lineage from forest and open landscapes. BMC Evolutionary Biology 8: 1193. https://doi.org/10.1186/1471-2148-8-193
Rheindt, F., L. Christidis, and J.A.
Norman. 2009. Genetic introgression, incomplete lineage sorting and faulty
taxonomy create multiple cases of polyphyly in a montane clade of
tyrant-flycatchers (Elaenia,
Tyrannidae). Zoologica Scripta 38: 143-153. https://doi.org/10.1111/j.1463-6409.2008.00369.x
Sclater, P.L. 1888. Catalogue of the birds in the British
Museum.
Volume 14. British
Museum, London.
Tang, Q.,
S.V. Edwards, and F.E. Rheindt. 2018. Rapid diversification and hybridization
have shaped the dynamic history of the genus Elaenia. Molecular Phylogenetics and Evolution 127: 522-533. https://doi.org/10.1016/j.ympev.2018.05.008
Zimmer,
J.T. 1941. Studies of Peruvian
birds. No. XXXVI. The genera Elaenia
and Myiopagis. American Museum
Novitates 1108.
Tom Schulenberg, March 2019
Comments from Remsen:
“A. YES. These new
data require re-elevating olivina to
species rank.”
“B. YES. ‘Tepui’
makes sense and is already in use.”
“C. YES. In addition
to enormous geographic disparity noted in the proposal, this is also not a
typical parent-daughter split because the daughters are NOT sisters; thus, this
a correction of the classification and a restoration of olivina to species rank, as in Hellmayr (1927), which was there
called “Roraima Elaenia” (when known only from the type locality), and thus no
longer strictly appropriate. Therefore,
in my view, there is no need to create new English names for both
pseudo-daughters, in that olivina
should never have been included with Sierran Elaenia and thus maintaining
Sierran Elaenia emphasizes this.”
Comments from Stotz:
“A. YES.
Seems like a straightforward split.
“B. YES. Tepui Elaenia
seems like a reasonable name for olivina.
“C. YES. I favor
maintaining Sierran Elaenia for pallatangae
(sensu stricto). Nearly everybody who has seen pallatangae has seen the Andean form. I don’t think it will confuse anybody to
continue to use Sierran Elaenia.”
Comments from Claramunt:
“A. YES.
Lumping them based on similarity was a historical error.”
Comments
from Robbins:
“YES. A very straightforward proposal, Yes to elevating the tepui (I support
that English name; very appropriate) olivina
to species status. As an aside, I would
also support continuing to use Sierran Elaenia for pallatangae sensu stricto.”
Comments
from Zimmer:
A. “YES to splitting olivina and davidwillardi from the pallatangae group, as strongly supported
by genetic data and in concert with expectations based upon biogeography. Yet another case of correcting a “lump” that
was based upon nothing more than similarity in plumage characters, in a group
where plumage evolution has proven to be extraordinarily conservative.
B. “YES to using ‘Tepui
Elaenia’ as the English name for olivina/davidwillardi.
The name is already in use in some quarters, and, it is entirely
appropriate, conveying much more information than any attempt at hairsplitting
descriptive names based upon plumage or morphology.
C.“YES to retaining ‘Sierran
Elaenia’ for pallatangae. The name is well established, pallatangae has a larger geographic
distribution than olivina/davidwillardi, and it is by far the more familiar of
the two pseudo-daughters, which, as Van points out, are not sister-taxa, and
which never should have been lumped in the first place.”
Comments from Areta: “YES.
The genetic data supports the split. I regret that no vocal analysis was
carried out. Bearing on the treatment of pallatangae
is also the paper by Chattopadhyay et al. BMC Evolutionary Biology (2017)
17:210, where the authors propose to treat Elaenia
albiceps chilensis and nominate pallatangae
as a single species: E. pallatangae.
“A. Tepui Elaenia sounds ok, although it is a little
confusing, given that E. dayi is also an Elaenia inhabiting the Tepuis. Thus, even when the
name sounds unique, it is not the only Elaenia
there.
“B. Yes. I am in favor of retaining names when they can be
easily assigned to a population and do not cause confusion.”
Comments from Stiles: “A. YES to split olivina from pallatangae;
B. YES to Tepui Elaenia; C. YES to Sierran Elaenia.
Comments from Jaramillo: “A. YES, molecular
data, morphology, biogeography etc all are clear that olivina is a species.
“B. Tepui Elaenia
sounds reasonable, so YES.
“C. YES, retain Sierran Elaenia for pallatangae.”
Comments from Pacheco: “A. YES. The evidence now available allows us rectify
the erroneous relationship between these two groups.”