Proposal (501) to South American Classification Committee
Given the committee rejected merger of Lurocalis, Nyctiprogne, “Caprimulgus” nigrescens, Nyctidromus, and “Caprimulgus” anthonyi in an all encompassing monophyletic genus that would represent the clade defined by the molecular results of Han et al. (2010), this proposal amends the earlier proposal (#465) by restricting the number of taxa to be transferred to Hydropsalis and to provide a tentative treatment for the above taxa not transferred to Hydropsalis.
See either proposal 465 or Han et al. (2010) for the data set and philosophy of proposed taxonomic and nomenclatural changes.
Briefly, 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, given that the type specimen for the genus is C. europaeus.
This proposal excludes the above taxa from the New World clade 3 of Han et al. (2010), which consisted of caprimulgine genera Hydropsalis, Uropsalis, Eleothreptus, Nyctidromus, and Caprimulgus (in part), and the chordeiline genera Nyctiprogne and Lurocalis. The following Caprimulgus spp. are interspersed with the above genera: cayennensis, maculicaudus, longirostris, whitelyi, parvulus, anthonyi, and nigrescens.
Below is the tree from Han et al.:
Within New World clade 3 as outlined by Han et al. (2010), the genera Eleothreptus, Uropsalis, several species included in Caprimulgus (see above tree and comments), and of course former members of Hydropsalis would be transferred to Hydropsalis. Based on committee member comments it was clear that members were not comfortable with including Lurocalis, Nyctiprogne, “Caprimulgus” nigrescens, Nyctidromus, and “Caprimulgus” anthonyi in the transfer. No nomenclatural issues are created by not transferring Lurocalis, Nyctiprogne and Nyctidromus; however, “Caprimulgus” nigrescens and “C.” anthonyi dictate some tentative changes. The Han et al. (2010) data set suggests that anthonyi is sister to Nyctidromus; thus anthonyi can be placed in that genus. Given the uncertain taxonomic affinities of nigrescens, that species can be placed in the genus Nyctipolus given that Ridgway (1912) designated Caprimulgus nigrescens as the type of that genus.
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.
Ridgway, R. 1912. Diagnoses of some new genera of American birds. Proc. Biol. Soc. Washington 25:97-102.
Mark Robbins, August 2011
Comments from Stiles: “A qualified YES. Actually, this proposal should be presented in a stepwise fashion, as there are various points where alternative decisions are possible given the phylogeny, and it is still not clear how many genera should be recognized. For instance:
“In clade NW2, do we recognize Podager as distinct from Chordeiles, given the deepness of this branch? And should the seemingly different pusillus be included in Podager or split in the genus Nannochordeiles?
“In clade NW3, I have no objection to splitting Lurocalis and Nyctiprogne, and no severe objection to splitting off Nyctidromus from Hydropsalis (presumably with anthonyi, which I am not acquainted); nigrescens does seem to merit generic recognition as Nyctipolus given the deepness of its branch.
“In clade NW1, things get a bit more complicated. Presumably most of this clade will go into Antrostomus, but what about Phalaenoptilus, the depth of its branch being quite comparable to that of Lurocalis or Nyctidromus in NW3, or Podager in NW2? The recognition of Nyctiphrynus seems reasonable, and certainly Siphonorhis is recognizable as well.
“In sum, I suspect that several of these points are worth getting opinions from other SACC members (although some, like Phalaenoptilus and Siphonorhis, are extralimital and probably best left up to NACC).”
Additional comments from Robbins: “Points made by Gary concerning Phalaenoptilus and Siphonorhis are beyond the scope of this committee. We dealt with Podager in another proposal. Intriguingly, the voice of anthonyi is quite similar to Nyctidromus (Robbins et al. 1994. Condor 96:224-228; listen to audio examples at the Macaulay Library website); thus, including them in the same genus seems appropriate given current genetic data.”
Comments from Pacheco: “YES. I have no objection to putting all of these taxa (with short phrases songs) in enlarged Hydropsalis except "Caprimulgus" parvulus. For this we can use Setopagis Ridgway,1912.”
Comments from Pérez: “A tentative YES. Molecular data and ecological and vocal similarities/differences support recognition of an expanded Hydropsalis while keeping Lurocalis, Nyctiprogne, and Nyctidromus (including C. anthonyi). Generic recognition for C. nigrescens, as Nyctipolus, is also supported by the available data. However, Fernando indicated “C.” parvulus should be recognized as a different genus, Setopagis, but without providing information supporting this recognition. If we recognize “C.” parvulus as a different genus, then we face the problem of weakly supported nodes that argue against an expanded Hydropsalis but in favor of at least four clearly molecular distinctive groups. Not an easy decision and, as a consequence of this, we might end with more genera than currently known but with better data.”
Comments from Jaramillo: “YES – this is easier for me to accept than the previous re-arrangement.“
Comments from Nacho Areta and Mark Pearman: “We believe that there are several serious shortcomings in treating all these nightjars under a much expanded genus Hydropsalis and agree with Gary’s proposal that this proposal should be split in several, each to be studied with care. Some of the points that can be raised against it are:
1) Three branches within the expanded Hydropsalis have
low bootstrap support, suggesting that other topologies are more likely to
appear in different analyses including more genes and taxa.
2) Although Fernando (Pacheco) mentions that all Hydropsalis would have songs with short phrases, Uropsalis has very long songs and the diversity of vocal sounds and flight-displays in the group is striking. For example, Setopagis (parvulus) has a very differently patterned song to that of C. maculicaudus, which has a flight display unknown in parvulus. On the other hand, the songs of maculicaudus and cayennensis are structurally very similar exactly as the case of Nyctidromus anthonyi and N. albicollis.
3) There are no data for Macropsalis, another long-tailed genus that may fit in Hydropsalis sensu stricto.
4) There are no data for 'Eleothreptus' candicans, which has a unique display incorporating mechanical wing sounds. Eleothreptus may well be worth recognition as a different genus (both are open-habitat species with big rounded heads and oddly patterned wings, with only remigial secondaries in anomalus).
5) It is not clear what we gain in understanding by merging all this highly divergent birds in a single genus. This large Hydropsalis seems taxonomically unbalanced in comparison to, for example, Chordeiles (whose members are similar in structure, even the small pusillus or the big nacunda) or Nyctidromus, not to mention the very-consistently distinct Lurocalis. We clearly know little about Neotropical nightjars, but merging all these birds under a single genus does not seem to bring any good prospect in learning more about them. Our hunch is that if Hydropsalis is enlarged now, the near future will demand it to be re-split as we gain more detailed knowledge about this set of very different birds. Indeed, our fragmentary actual knowledge serves to argue against their merger.”
Additional comments from Jaramillo: “I am changing my vote to a NO based on Mark and Nacho's comments. While this current option is better than the previous, upon second thought merging all of that diversity in one genus does seem to be something that will be regretted in the future. I think that dividing this up into several separate issues may resolve what best to do with these species.”
Comments from Zimmer: “NO. From an intuitive standpoint, some of this proposal makes sense and some of it doesn’t. As someone who philosophically prefers more narrowly defined, internally cohesive genera, I am opposed to lumping so much diversity into an expanded Hydropsalis. I too, think that further data, particularly as regards vocalizations, display behaviors, and general ecology will reveal a need for recognizing more genera. At the very least, I echo the comments made by Gary, Nacho, and Mark Pearman that this proposal should be split up into component parts that we can deal with separately.”
Comments from Remsen: “NO. Echoing the sentiments of others, I think that such Hydropsalis defined this broadly would be out of line with the subjective notion of a genus having morphological themes and continuity, especially compared to other caprimulgid genera.”
Comments from Nores: “NO. See proposal #521.”