Proposal (466) to South American Classification Committee
Transfer Caprimulgus rufus and Caprimulgus sericocaudatus to the genus Antrostomus
Han et al. (2010) published a molecular based phylogeny of Caprimulgidae from more than 60% of caprimulgid species and 14 of 16 currently recognized genera. The taxon sampling was broad and included all morphologically divergent lineages. New World taxa were particularly well represented. DNA sequences were collected from the entire mitochondrial DNA cytochrome b gene and parts of two nuclear genes (myelocytomatosis viral oncogene homolog and growth hormone). All analyses of the 72 ingroup plus outgroup taxa were conducted on the 4179 characters. The Han et al. (2010) phylogeny was well resolved and in substantial agreement with all previous molecular work on the family (Sibley and Ahlquist, 1990; Mariaux and Braun, 1996; Barrowclough et al., 2006; Larsen et al., 2007; Braun and Huddleston, 2009).
In proposing a new classification, Han et al. (2010) used the following criteria: foremost, all named taxa represented monophyletic groups. Second, for stability of the named taxa, whenever possible, currently recognized taxa were retained, and when more than one partitioning scheme for a clade was plausible, they opted for the one that was more likely to remain viable in the face of new data.
Within core caprimulgids, four strongly supported major clades (3 New World, 1 Old World) provided a natural partitioning scheme, but numerous taxa needed to be reassigned to reflect the non-monophyly of the current genus Caprimulgus. Additionally, a number of small or monotypic genera should be subsumed. Caprimulgus Linnaeus 1758 should be restricted to the Old World clade, since the type specimen for the genus is Caprimulgus europaeus.
Here is the tree from Han et al.:
Of taxa that are germane to SACC within Han et al.’s (2010) New World clade 1, Nyctiphrynus remains as currently constituted. Caprimulgus rufus is transferred to the genus Antrostomus Bonaparte 1838, which has priority among available names for this clade (Peters 1940). Although not included in the Han et al. (2010) study, Caprimulgus sericocaudatus is also assigned to Antrostomus. The allocation of sericocaudatus to Antrostomus is based on its placement in a species group with salvini and badius by Cleere (1999), and more importantly, an unpublished molecular data set using different genes than Han et al. (2010) by Snorri Sigurdsson and Joel Cracraft (2010) demonstrated that C. sericocaudatus is sister to C. rufus and C. carolinensis and thus belongs in the Antrostomus clade. Although C. carolinensis is a North American breeding species occurring in SACC area only in winter, it is the sister species to C. rufus and should thus also follow that species into Antrostomus.
Barrowclough, G.F., Groth, J.G., Mertz, L.A. 2006. The RAG-1 exon in the avian order Caprimulgiformes: phylogeny, heterozygosity, and base composition. Mol. Phylogenet. Evol. 41:238–248.
Braun, M.J., Huddleston, C.J. 2009. A molecular phylogenetic survey of caprimulgiform nightbirds illustrates the utility of non-coding sequences. Mol. Phylogenet. Evol. 53:948–960.
Cleere, N. 1999. Family Caprimulgidae (Nightjars). In: del Hoyo, J., Elliott, A., Sargatal, J. (Eds.), Handbook of the Birds of the World, Barn Owls to Hummingbirds, vol. 5. Lynx Edicions, Barcelona, pp. 302–386.
Han, K.-L., Robbins, M.B., Braun, M.J. 2010. A multi-gene estimate of phylogeny in the nightjars and nighthawks (Caprimulgidae). Mol. Phylogenet. Evol. 55:443-453.
Larsen, C., Speed, M., Harvey, N., Noyes, H.A. 2007. A molecular phylogeny of the nightjars (Aves: Caprimulgidae) suggests extensive conservation of primitive morphological traits across multiple lineages. Mol. Phylogenet. Evol. 42:789–796.
Mariaux, J., Braun, M.J. 1996. A molecular phylogenetic survey of the nightjars and allies (Caprimulgiformes) with special emphasis on the potoos (Nyctibiidae). Mol. Phylogenet. Evol. 6:228–244.
Peters, J.L. 1940. Checklist of Birds of the World. Harvard University Press, Cambridge.
Sibley, C.G., Ahlquist, J.E. 1990. Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale University Press, New Haven, London.
Sigurdsson, S., Cracraft, J. 2010. A species-level phylogeny of the nightjars (Caprimulgidae). Poster at International Ornithological Congress, Campos de Jordão, Brazil.
Mark Robbins, September 2010
Comments from Stiles: “YES – this clade also seems strongly supported, with only Siphonorhis and Nyctiphrynus perhaps meriting generic separation from Antrostomus (I note that carolinensis, not mentioned in the proposal, also falls into Antrostomus).”
Comments from Nores: “YES. Es evidente en el análisis molecular de Han et al. (2010) que C. rufus y C. carolinensis forman un clado que incluiría también a C. sericocaudatus (en base a un análisis no publicado de Snorri Sigurdsson and Joel Cracraft). Pero ver respuesta a propuesta #441.”
Comments from Remsen: “YES. There really aren’t any other options, although Mark did not address what will happen in terms of classification with the whip-poor-will group, presumably because it is extralimital. Given the overall similarity in voice and morphology, I would favor expanding the boundaries of this genus to include the node with support value 96 that includes not only the whip-poor-will group but also Phalaenoptilus. To maintain the latter as a monotypic genus when in the previous proposal Lurocalis and, for example “C.” parvulus are merged into one genus is inconsistent in my opinion. Even including Nyctiphrynus with Antrostomus would produce a less heterogeneous group than broad Hydropsalis.”
Comments from Zimmer: “YES. This move seems strongly supported by the molecular data and makes sense on the grounds of vocal and morphological characters. I would echo Van’s suggestion to include the extralimital whip-poor-will group (and include Phalaenoptilus) in Antrostomus, although I wouldn’t go so far as to include Nyctiphrynus, which, to me, seem to be pretty different in a number of respects.”
Comments from Pacheco: “YES. Considero a proposta bem apoiada pelos dados disponíveis.”
Comments from Jaramillo: “YES. The molecular data are strong, and vocalizations and other natural history considerations suggest that this is a solid group, and not part of the true Caprimulgus of the Old World. I also question why the whip-poor-will group was left out of the discussion, presumably as they are not Neotropical species, but it would be good to know that it isn’t for a taxonomic reason we should be aware of.”
Comments from Pérez: “YES, I think molecular data presented by Han et al. (2010) strongly support this group. I like Van’s proposal but also expanding Antrostomus would need to consider Phalaenoptilus within this genus, a decision to which I don’t have a strong opinion. Phylogenetically and based on vocal (based on Kevin’s comments) and morphological grounds, it would make sense but considerations of its physiology might support placement in its own genus. Either one would make sense depending on the weight we give to each character and on our definition of a genus (which could be based on different criteria). Maybe we need to discuss these issues to be consistent when evaluating different proposals. Going back to Van’s proposal, excluding Phalaenoptilus from Antrostomus would force to define another genus for the node including C. vociferus (whip-poor-will) as there is no strong support for the node suggesting both groups of ex-Caprimulgus are sister taxa.”