Proposal (951) to South American Classification Committee

Note from Remsen: This is a proposal also submitted to NACC by Shawn, where it passed unanimously.

Transfer Pitangus lictor to monotypic genus Philohydor

Background: Lanyon (1984) described the genus Philohydor for Lesser Kiskadee (Pitangus lictor), which had typically been placed in the genus Pitangus together with Great Kiskadee (Pitangus sulphuratus), on the basis of morphological and behavioral differences. In justifying his split of Philohydor from Pitangus, Lanyon (1984) noted differences in syringeal morphology that “far exceed intrageneric variation in syringeal morphology among tyrant flycatchers” that include differences in the number of complete cartilage rings, as well as differences in the shapes of cartilage rings. In addition to syrinx morphology, Philohydor is described as having a very narrow skull and differs from Pitangus “to a degree greater than any other congeneric flycatchers examined” (Warter 1965 in Lanyon 1984). Lanyon (1984) also noted differences in nest shape between Philohydor and Pitangus, with Philohydor constructing a shallow cup-nest, while Pitangus constructs a large and untidy domed structure. Despite these differences, many checklists continued to recognize lictor as part of Pitangus (Dickinson and Christidis 2014, Clements et al. 2021, AOS 1998), although the IOC Checklist (Gill et al. 2022) and BirdLife International Checklist (del Hoyo and Collar 2016) place lictor in Philohydor. Early genetic work did not provide much clarification of the issue; Tello et al. (2009) found that Great Kiskadee and Lesser Kiskadee were sister species, though with relatively weak support.

New Information: In their phylogeny of suboscine passerines, which included 1,287 of 1,306 suboscine species sequenced at 2,389 genomic regions, Harvey et al. (2020) found that Lesser Kiskadee and Great Kiskadee were not sister taxa, with Lesser Kiskadee instead sister to a large clade that included Great Kiskadee, Myiozetetes, Tyrannus, Conopias, and Myiodynastes (among others). The nodes that connect Lesser Kiskadee and Great Kiskadee to the rest of the phylogeny both receive very strong support (98 and 100 RAxML bootstrap support, respectively; Fig. 1). Given that Lesser Kiskadee and Great Kiskadee are not sister species, and neither species is particularly closely related to any other species, placing each in a monotypic genus seems to be the best solution. For Lesser Kiskadee, this involves resurrecting Philohydor Lanyon, 1984 and removing it from Pitangus, leaving Great Kiskadee as the sole member of Pitangus.

Recommendation: I recommend that NACC transfer Lesser Kiskadee (Pitangus lictor) from the genus Pitangus to the monotypic genus Philohydor.

References

American Ornithologists’ Union (1998) Check-list of North American birds. Seventh edition. American Ornithologists’ Union, Washington, D.C., U.S.A.

Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, J. A. Gerbracht, D. Lepage, B. L. Sullivan, and C. L. Wood (2021) The eBird/Clements checklist of birds of the world: v2021

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, Spain

Dickinson, E. C., and L. Christidis, Editors (2014) The Howard and Moore Complete Checklist of the Birds of the World. Fourth Edition. Volume 2. Aves Press, Eastbourne, United Kingdom

Gill, F., D. Donsker, and P. Rasmussen, Editors (2022) IOC World Bird List (v12.1)

Harvey, M. G., G. A. Bravo, S. Claramunt, A. M. Cuervo, G. E. Derryberry, J. Battilana, G. F. Seeholzer, J. S. McKay, B. C. O’Meara, B. C. Faircloth, S. V. Edwards, J. Pérez-Emán, R. G. Moyle, F. H. Sheldon, A. Aleixo, B. T. Smith, R. T. Chesser, L. F. Silveira, J. Cracraft, R. T. Brumfield, and E. P. Derryberry (2020) The evolution of a tropical biodiversity hotspot. Science 370: 1343-1348

Lanyon, W. E. (1984) A phylogeny of the kingbirds and their allies. American Museum Novitates 2797: 1-28

Tello, J. G., R. G. Moyle, D. J. Marchese, and J. Cracraft (2009) Phylogeny and phylogenetic classification of the tyrant flycatchers, cotingas, manakins, and their allies (Aves: Tyrannidae). Cladistics 25: 429-467

Figure 1. Portion of tree from Harvey et al. (2020) with tip names and support values. Lesser Kiskadee is indicated with a red arrow with the name “Philohydor” and Great Kiskadee is indicated with a light blue arrow and the name “Pitangus”

Shawn M. Billerman, July 2022

Comments from Remsen: “YES. Genetic data now require this change. The differences in skull morphology, syringeal morphology, and nest structure have been known for a long time, and their shared plumage patterns are clearly just retained ancestral character states in a broader lineage that shares these patterns to varying degrees; alternatively, this may be a case of social mimicry in that lictor’s water-edge habitat is always shared with sulphuratus.”

Comments from Robbins: “YES. I vote for placing lictor in Philohydor. Based on the Lanyon data, I thought we had done this a long time ago!”

Comments from Claramunt: “YES. A classic problem finally resolved.”

Comments from Areta: “YES. The phylogenetic placement of lictor as sister to numerous highly differentiated genera, coupled to its distinctive syrinx, and nesting behavior support the retention of Philohydor for lictor. Placing it in Pitangus is untenable. Another glorious contribution by Wesley Lanyon.”

Comments from Stiles: “Definitely YES and long overdue!”

Comments from Lane: “YES. I honestly didn't realize this wasn't already the case! I've always thought that considering P. lictor as Pitangus didn't make sense once I got to know the bird. Better to put it in a separate genus.”

Comments from Bonaccorso: “YES. The paraphyly of Pitangus is clear and supported by a lot of loci. Mark is right, but still, having so much molecular data backing up Lanyon’s brilliant conclusions is very reassuring.”

Comments from Zimmer: “YES, a slam-dunk in my opinion, for all of the reasons first elaborated by Lanyon, and now, fortified by recent genetic data. Like some others on the committee, I too was somehow operating under the impression that this change had been made ages ago!”

Comments from Pacheco: “YES. Sufficient evidence presented long ago.”