Proposal (742) to South American Classification Committee
Elevate Celeus flavescens ochraceus to species status
Effect on SACC list: elevate subspecies Celeus [flavescens] ochraceus to species
Background: The variable forms (e.g., color photo, Fig. 6; Benz and Robbins 2011) of eastern Brazilian ochraceus traditionally have been treated as a subspecies of the southeastern Brazilian C. flavescens (Short 1972, 1982).
New Information: Benz and Robbins (2011) presented a well-supported molecular data set for the entire genus Celeus. Germane to this proposal, the mtDNA and combined data analyses indicate ochraceus is ancestral in a clade that included flavescens, elegans and lugubris (figs. 1, 4). Ochraceus exhibited the highest mitochondrial genetic divergences within that clade and was genetically distinct from nominate flavescens at the HMGN2 nuclear locus. In addition to these genetic differences between ochraceus and flavescens, ochraceus differs dramatically in plumage and size from flavescens (Short 1972, 1982; Benz and Robbins 2011, fig. 6). Nonetheless, some populations of ochraceus closely resemble in plumage C. flavescens intercedens, where the two taxa come into contact in southern Tocantins, northern Goiás, and western Bahia (V. Piacentini, pers. comm.). Short (1972) stated that intercedens is variable in plumage and intermediate in size between smaller ochraceus and larger nominate flavescens. Intercedens was not represented in the Benz and Robbins (2011) data set and thus its taxonomic status remains undetermined. It may prove that there is gene flow between ochraceus and C. flavescens intercedens not unlike between recognized species-level C. elegans and C. lugubris (Short 1972, 1982).
Recommendation: We recommend a YES vote for recognizing ochraceus as a species as this is the most genetically distinct in the flavescens, elegans and lugubris clade, and in plumage morphology it is as distinct as other recognized species within the clade.
Benz, B.W. and M.B. Robbins. 2011. Molecular phylogenetics, vocalizations and species limits in Celeus woodpeckers (Aves: Picidae). Molecular Phylogenetics and Evolution 56:29-44.
Short, L.L. 1972. Relationships among the four species of the superspecies Celeus elegans (Aves: Picidae). American Museum Novitates 2487.
Short, L.L. 1982. Woodpeckers of the World. Delaware Museum of Natural History. Greenville, Delaware.
Mark Robbins and Brett Benz, February 2017
Comments from Stotz: “A tentative YES. Ideally we’d know more about intercedens, but given the genetic relationships among these Celeus and the morphology of these birds, I think the treatment of splitting ochraceus makes the most sense.”
Comments from Stiles: “YES, based primarily on genetics and plumage. The intercedens situation is intriguing - could this form be an ochraceus population mimicking flavescens? Such mimicry has been found in another species of this genus.”
Comments from Cadena: “YES. I should clarify that what the phylogenetic analysis shows is that ochraceus is the sister group to a clade including flavescens, elegans, and lugubris; it is by no means ancestral to these taxa as the proposal states. Nonetheless, the phylogenetic results provide strong support for the proposed change. Although I do not think that species need to be monophyletic (i.e. under the BSC), it would be hard to argue for conspecificity of ochraceus and flavescens to the exclusion of elegans and lugubris given the phylogeny and phenotypic variation.”
Comments from Zimmer: “YES, for reasons particularly well stated by Daniel. The situation with intercedens is puzzling, but, as Gary and Alvaro noted, woodpeckers don’t follow all the same ‘rules’, and there could always be factors such as ISDM involved. Certainly, ochraceus and flavescens are as or more different from one another in plumage than either is compared to elegans and lugubris.”
Comments from Jaramillo: “YES. An intriguing possibility suggested by Gary regarding possible mimicry explaining intercedens. We shall have to see. Overall, I find woodpeckers troubling. Plumage often converges, partly due to mimicry based on recent findings, and partially on habitat/ecology. But also there is a general tendency in some groups for hybridization, whereas other groups have geographic variation that is striking and noteworthy. I am making no other point here than to say that woodpeckers seem to “function” in a way different from various other groups we contend with, and more molecular work is definitely necessary with dense taxon sampling, as well as a better understanding on what barriers to gene flow members of this group respond to. Oddly enough plumage coloration is not always one of them!”
Comments from Areta: "YES. The impressive differences in size and plumage between ochraceus and flavescens support, in principle, the recognition of C. ochraceus. However, the situation with C. flavescens intercedens and the local forms of ochraceus with which it would overlap in Tocantins, Bahia and Goiás clearly merits more study, as does a study on vocalizations, geographic variation in plumage and genetics of ochraceus."
Comments from Pacheco: "YES. In fact, the status of C. f. intercedens is intriguing. It needs to be better understood. However, I emphasize that there are good grounds for treating C. f. ochraceus as a separate species."
Comments from Claramunt: "YES. Plumage and phylogeny indicate that ochraceus is a different species."