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.
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.
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
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.”