Proposal (697) to South American Classification Committee
Elevate Asthenes vilcabambae ayacuchensis to species rank
Effect on South American Checklist: This proposal is to split Asthenes vilcabambae into two species: Asthenes vilcabambae of western Cuzco and extreme SE Junin and Asthenes ayacuchensis of eastern Ayacucho, Peru.
Background: Vaurie et al. (1972) described two new thistletail subspecies from Southern Peru: Asthenes fuliginosa vilcabambae and A. f. ayacuchensis. However, Vaurie’s views on species limits in Furnariidae were conservative– he treated all Andean thistletails (then ascribed to the genus Schizoeaca) as a single species. Subsequent authors (e.g. Remsen 1981, FjeldsĆ and Krabbe 1990, Remsen 2003) treated A. f. vilcabambae and A. f. ayacuchensis as a single species (A. vilcabambae), although noting the presence of plumage differences between the two subspecies.
New information: Hosner et al. (2015) investigated the vocalizations and molecular phylogenetic relationships of A. v. vilcabambae and A. v. ayacuchensis. Phylogenetic analysis of ND2 and FGB-5 found A. vilcabambae paraphyletic. Asthenes. v. vilcabambae was found sister to A. pudibunda with strong support (1.0 posterior probability/ 97% of ML bootstraps), and A. v. ayacuchensis was related to A. palpebralis and A. ottonis with strong support (1.0 PP/ 89% ML BS). Within the later trio, A. v. ayacuchensis was sister to A. palpebralis, but with weak support (0.83 PP/57% ML BS). Vocalizations of A. v. vilcabambae and A. v. ayacuchensis differed substantially. Song of A. v. ayacuchensis was more similar to A. palpebralis than it was to A. v. vilcabambae (recordings archived at Macaulay Library).
Recommendation: In light of new vocal and molecular phylogenetic evidence, I recommend a “YES” vote to add Asthenes ayacuchensis to the SACC list. I recommend “Ayacucho Thistletail” for an English name, highlighting its restricted known distribution in eastern Ayacucho, Peru.
FJELDSĀ, J. AND N. KRABBE. 1990. Birds of the high Andes: a manual to the birds of the temperate zone of the Andes and Patagonia, South America. Zoological Museum, University of Copenhagen, Copenhagen, Denmark.
HOSNER, P.A., L. CUETO-APARICIO, G. FERRO-MEZA, D. MIRANDA, AND M.B. ROBBINS. 2015. Vocal and molecular phylogenetic evidence for recognition of a thistletail species (Furnariidae: Asthenes) endemic to the elfin forests of Ayacucho, Peru. Wilson Journal of Ornithology 127:724–765.
REMSEN JR., J. V. 1981. A new subspecies of Schizoeaca harterti with notes on taxonomy and natural history of Schizoeaca (Aves: Furnariidae). Proceedings of the Biological Society of Washington 94:1068–1075.
REMSEN JR., J. V. 2003. Family Furnariidae (ovenbirds). Pages 162–357 in Handbook of the birds of the world. Volume 8. Broadbills to tapaculos (J. del Hoyo, A. Elliott, and D. A. Christie, Editors). Lynx Edicions, Barcelona, Spain.
VAURIE, C., J. WESKE, AND J. TERBORGH. 1972. Taxonomy of Schizoeaca fuliginosa (Furnariidae), with description of two new subspecies. Bulletin of the British Ornithologists’ Club 92:142–144.
Peter A. Hosner, January 2016
Comments by Remsen: “YES. The genetic and vocal data require the change, and the obvious solution is to elevate ayacuchensis to species rank, as indicated in the proposal. I wish they were all this easy. I also like the proposed English name.”
Comments from Stiles: “YES. Plumage, vocalization and genetics all indicate that ayacuchensis cannot be retained in vilcabambae, and that species designation of the former is appropriate, along with the suggested English name.”
Comments from Claramunt: “YES. Multiple phenotypic differences (plumage, vocal) together with phylogenetic evidence clearly indicate that ayacuchensis is a separate species. The proposed English name is adequate.”
Comments from Zimmer: “YES. The strongest possible case, when morphological, vocal and genetic data sets all point in the same direction. I like the suggested English name as well.”
Comments from Areta: “YES. The coincidence of all lines of evidence strongly argues in favor of the split.”
Comments from Pacheco: “YES The set of available evidence is very persuasive.”
Comments from Jaramillo: “YES. The fact that the thistletails are not a monophyletic group is still amazing to me. But that is neither here nor there. The vocal and molecular data stack up, and this taxon needs to be elevated to species level.
“YES also to the English Name, Ayacucho Thistletail.
Just in case, a link to the paper is at: https://www.researchgate.net/profile/Peter_Hosner/publication/289693893_Vocal_and_Molecular_Phylogenetic_Evidence_for_Recognition_of_a_Thistletail_Species_Furnariidae_Asthenes_Endemic_to_the_Elfin_Forests_of_Ayacucho_Peru/links/5693bb5008aeab58a9a2a62c.pdf
Comments from Robbins: “YES. Vocal, plumage morphology, and genetics support recognizing Asthenes vilcabambae as a species.”