Proposal (845) to South American Classification Committee
Synonymize Picumnus fulvescens with Picumnus limae and revise the linear sequence of Picumninae
Effect on SACC list: Remove one name (Picumnus fulvescens) from the list and revise the linear sequence of Picidae (Picumninae).
Background: Ochraceous Piculet Picumnus limae and Tawny Piculet Picumnus fulvescens are two similar woodpeckers mainly distinguished by their plumage coloration (white/light yellow vs rusty brown) and their presumed disjunct distribution (Short 1982, Winkler & Christie 2002). They were generally treated as full species (for all references, see the systematic section in Lima et al. 2020), although a single author treated fulvescens as subspecies of P. limae (Pinto 1978). Some authors (e.g. Olmos et al. 2005, Araujo 2009) already doubted that these woodpeckers were separate species and identified a few areas where both typical morphs occur in syntopy with intermediate morphs, but no one has provided evidence to support any change in current taxonomy.
New information: Lima et al. (2020) presented a taxonomic reassessment with evidence for the treatment of a single species, based on the largest and most widely distributed sample of individuals known so far.
Picumnus limae and P. fulvescens are distinguished by the respective white/light yellow versus ferruginous ventral coloration as well as their presumed disjunct distribution (Short 1982, Winkler & Christie 2002). Lima et al. (2020) demonstrated that individuals of both forms occur in syntopy across several locations and there are intermediate forms that cannot be reliably assigned to any of the species. These intermediate individuals are not restricted to the contact zone between the extreme phenotypes, but show a clinal pattern with lighter birds in north and darker birds in south of the distribution, supporting the existence of a single species with clinal variation in color. The recognition of two species was due to sampling gaps associated to small sample sizes. P. fulvescens is not diagnosable from P. limae by any morphological features or vocalizations. Therefore, Lima et al. (2020) propose that P. limae and P. fulvescens comprise a single species with a high degree of color variation and a clinal distribution.
In addition, the song is virtually identical in all morphs. Playback experiments of northernmost white birds readily responded to recordings of brown birds from the southeastern extreme of the distribution, and vice-versa, suggest that song recognition exists between extreme phenotypes (Lima et al. 2020). This absence of difference in vocalizations provides powerful information on the differentiation of these two supposed species, because there are no sympatric woodpecker species that are vocally indistinguishable (Remsen 2014).
Finally, it is worth noting that Short (1982, p. 91) suspected that P. fulvescens was related to P. nebulosus due to their similarity in the plumage color. This opinion was followed by all subsequent authors (e.g. Sick 1997, Winkler & Christie 2002). However, morphology and vocal characters support a relationship with P. spilogaster. This is also suggested by molecular and vocal analysis, which placed all piculets with trilled voice within the same group (Shakya et al. 2017, Lima 2018).
I recommend a YES vote to synonymize Picumnus fulvescens with Picumnus limae and change the linear sequence of Picumninae.
Araujo, H.F.P. (2009) Amostragem, estimativa de riqueza de espécies e variação temporal na diversidade, dieta e reprodução de aves em área de Caatinga, Brasil. PhD thesis, Universidade Federal da Paraíba.
Lima, H.S. (2018) Introgressão e deslocamento de caracteres numa zona de contato entre Picumnus varzeae e Picumnus cirratus macconnelli no rio Amazonas. Dissertation, Instituto Nacional de Pesquisas da Amazônia.
Lima, R.D., Tomotani, B.M. & Silveira, L.F. (2020) Colour variation and taxonomy of Picumnus limae Snethlage, 1924 and P. fulvescens Stager, 1961 (Piciformes: Picidae). Journal of Ornithology https://doi.org/10.1007/s10336-020-01745-0
Olmos, F., Silva, W.A.G. & Albano, C.G. (2005) Aves de oito áreas de Caatinga no sul do Ceará e oeste de Pernambuco, Nordeste do Brasil: composição, riqueza e similaridade. Papéis Avulsos de Zoologia, 45 (14), 179–199.
Pinto, O.M.O. (1978) Novo Catálogo das Aves do Brasil. Primeira Parte: Aves não Passeriformes e Passeriformes não Oscines, com exclusão da familia Tyrannidae. Empresa Gráfica da Revista dos Tribunais, São Paulo.
Remsen, J.V., Jr. (2014) [Review of] HBW and BirdLife International Illustrated Checklist of the Birds of the World Volume 1: Non-passerines. Journal of Field Ornithology, 86 (2), 182–187.
Shakya, S.B., Fuchs, J., Pons, J. & Sheldon, F.H. (2017) Tapping the woodpecker tree for evolutionary insight. Molecular Phylogenetics and Evolution 116, 182–191.
Short, L.L. (1982) Woodpeckers of the world. Delaware Museum of Natural History, Greenville.
Winkler, H. & Christie, D.A. (2002) Family Picidae (woodpeckers). In: Hoyo, J., Elliot, A. & Sargatal, J. (eds) Handbook of the birds of the world: Jacamars to Woodpeckers. Lynx Editions, Barcelona, pp 296–555.
Rafael D. Lima, January 2020
Comments from Areta: “YES to lumping P. fulvescens and P. limae. Lima et al. (2020) clearly showed that vocalizations are identical in their unique structure and in quantitative measurements (although no details were provided as to how the measurements were taken) and provide incidental information on responses of pale birds to recordings of dark ones. They also show the coexistence of differently colored individuals at several localities without any clear geographic break in the distribution of their pre-defined plumage categories, and overall, clinality explains the distribution of such plumage categories.
“I must stress that I am not endorsing the "synonymization" of fulvescens and limae, but rather their collective treatment within a single species. The discussion as to how to treat them nomenclaturally at an infraspecific category is a different one, and should also include the discussion on the priority of fulvescens over saturatus.”
Comments from Stiles: “Definitely YES to lumping fulvescens and limae.. in fact, recognizing the latter even at the subspecific level seems pretty dubious given the distribution of the phenotypes.
Comments from Claramunt: “YES. Rafael et al.’s study shows clearly that variation is gradual and not indicative of a species-level division.”
Comments from Jaramillo: “YES. Greater sample size and sampling localities show that this is a clinal change from darker cinnamon to paler buffy birds. As such fulvescens becomes conspecific with limae.”
Comments from Bonaccorso: “YES. This one seems very clear. Both very similar in plumage, with clinal variation, virtually next to each other, and responsive to playback.”
Comments from Zimmer: “YES to lumping fulvescens and limae. Although I’ve never conducted any playback trials, I’ve also never been able to distinguish between the voices of these two taxa and have been puzzled by seeing seemingly intermediate plumage types over the years, as well as by seeing phenotypically typical individuals of one taxon or the other in areas where I would have expected (based on geography alone) only the other taxon to occur.”
Comments from Robbins: “YES, for treating fulvescens as the same species as limae, and I agree with Gary’s comments that treating fulvescens as even a subspecies is questionable.”
Comments from Pacheco: “YES. The work of Rafael and colleagues has fully demonstrated that the treatment of a single species is the only one appropriate to refer to these two names described from extreme phenotypes of the same taxon.”
Comments from Remsen: “YES to both parts of the proposal. The data are solid – “fulvescens” has been shown to be an undiagnosable “grade” on a cline.
“No one has mentioned English names. If fulvescens (Tawny Piculet) were a true sister taxon to limae (Ochraceous Piculet), then technically we would need a new name to distinguish the new parental species from both daughters. However, because “fulvescens” has been show by Rafael et al. not to be a taxon per se, I think we can simply combine it into Ochraceous Piculet. If anyone is interested in reversing this, feel free to write a proposal.”