Proposal (880) to South American Classification Committee

Change linear sequence of species in Chaetura

This proposal would alter the current linear sequence of species in Chaetura based on phylogenetic information.

Background: SACC’s current linear sequence for the genus Chaetura is as follows (Remsen et al. 2020):

Chaetura spinicaudus

Chaetura cinereiventris

Chaetura egregia

Chaetura vauxi

Chaetura pelagica

Chaetura chapmani

Chaetura meridionalis

Chaetura andrei

Chaetura brachyura

NACC’s current linear sequence of Chaetura is (Chesser et al. 2020):

Chaetura pelagica

Chaetura vauxi

Chaetura chapmani

Chaetura brachyura

Chaetura meridionalis

Chaetura spinicaudus

Chaetura fumosa

Chaetura cinereiventris

Chaetura martinica

New Information:

Chesser et al. (2018) published a robust phylogeny (below) of the genus Chaetura based on combined nuclear and mitochondrial data from all of eleven species and 21 of 30 taxa recognized in the genus by Dickinson and Remsen (2013).

Their analysis confirmed that the genus is composed of two nearly equally sized subclades that correspond to recognized subgenera (Marin 2000): Acanthylis (the gray/pale rumped clade) and Chaetura (the brown-rumped clade).

Two species-level revisions of the taxonomy of the genus were mandated by this phylogenetic study, both of which were adopted with the passage of SACC 841 (https://www.museum.lsu.edu/~Remsen/SACCprop841.htm). Within the subgenus Chaetura, C. (v.) andrei was shown to be paraphyletic to other forms within C. vauxi, which led to the recognition of the former as a distinct species, and C. viridipennis, formerly treated as a distinct species, was reclassified as a subspecies of C. chapmani due to being embedded within the latter, with very low genetic divergence.

Resolution of the taxa within the subgenus Acanthylis was generally poor, especially for spinicaudus, martinica, fumosa and egregia.

Analysis:

Following the conventions of listing basal taxa and then less speciose taxa first within the sequence, the phylogeny of Chesser et al. (2018) can best be represented as follows for the NACC species:

(A)

Chaetura cinereiventris

Chaetura spinicaudus

Chaetura fumosa

Chaetura martinica

Chaetura pelagica

Chaetura vauxi

Chaetura chapmani

Chaetura meridionalis

Chaetura brachyura

The phylogeny would be best reflected by a linear sequence of the SACC list as follows:

(B)

Chaetura cinereiventris

Chaetura spinicaudus

Chaetura egregia

Chaetura pelagica

Chaetura vauxi

Chaetura chapmani

Chaetura andrei

Chaetura meridionalis

Chaetura brachyura

Recommendation: We recommend a YES vote by NACC members on (A) and a YES vote by SACC members on (B) to change the current sequences to the new sequences which better reflect the phylogeny proposed by Chesser et al. (2018) and which would also bring the two lists into agreement.

Literature Cited:

Chesser, R. T., H. Vaseghi, P. A. Hosner, L. M. Bergner, M. N. Cortes-Rodriguez, A. J. Welch, & C. T. Collins (2018). Molecular systematics of swifts of the genus Chaetura (Aves: Apodiformes: Apodidae). Molecular Phylogenetics and Evolution 128:162–171.

Chesser, R. T., S. M. Billerman, K. J. Burns, C. Cicero, J .L. Dunn, A. W. Kratter, I. J. Lovette, N. A. Mason, P. C. Rasmussen, J. V. Remsen, Jr., D. F. Stotz, and K. Winker (2020). Sixty-first Supplement to the American Ornithological Society’s Check-list of North American Birds. The Auk: Ornithological Advances. https://doi.org/10.1093/auk/ukaa030.

Dickinson, E. C. & Remsen, J. V. Jr. (Eds). 2013. The Howard & Moore Complete Checklist of the Birds of the World. 4th Edition, Volume 1 Non-passerines. Aves Press, Eastbourne, U.K.

Marín, M. 2000. Species limits, distribution, and biogeography of some New World gray-rumped spinetailed swifts (Chaetura, Apodidae). Ornitología Neotropical 11: 93-107.

Remsen, J. V., Jr., J. I. Areta, C. D. Cadena, S. Claramunt, A. Jaramillo, J. F. Pacheco, J. Perez Emán, M. B. Robbins, F. G. Stiles, D. F. Stotz, and K. J. Zimmer (Version 11 February 2020). A classification of the bird species of South America. American Ornithological Society. http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm

David B. Donsker and Pamela C. Rasmussen, 11 August 2020

Comments from Stiles: “YES to the change in sequence for these South American Chaetura. I note that NACC has some further work to do, given that as it stands, the genetic evidence strongly suggests that both cinereiventris and spinicauda are para- or polyphyletic!”

Comments from Zimmer: “YES. This would bring us in line with the linear sequence already adopted by NACC, and would be consistent with the changes in species-limits that we have already made, based upon the same work by Chesser et al. (2018).”

Comments from Jaramillo: “YES – the published data look solid. I do wonder if there might be an argument for elevating the subgenera to genera? I don’t know, just mention it in case someone is keen on taking that on.”

Comments from Pacheco: “YES. For compatibility with the NACC.”

Comments from Bonaccorso: “YES. It makes sense in light of the phylogeny and to be consistent with NACC.”

Comments from Claramunt: “NO. Shouldn’t vauxi be listed before pelagica, as it is distributed more to the northwest?”