Proposal (349) to South American Classification Committee
Separar Pyrilia coccinicollaris de Pyrilia haematotis
Antecedentes: Pyrilia coccinicollaris ha sido generalmente considerada una subespecie de Pyrilia haematotis ya que se consideraba que pesar de que ambas habitaban Panamá no había simpatría entre ellas, porque haematotis ocupaba el este del país y coccinicollaris el oeste. Cracraft y Prum (1988), usando caracteres externos del género, codificados binariamente en primitivo o derivado, encuentran diferencias como para separar las dos especies.
Nueva información: Análisis moleculares llevados a cabo por Ribas et al. (2005), mostraron claramente que, a pesar de la similitud fenotípica entre ambos taxas, las diferencias interespecíficas eran marcadamente más altas (2.6% in ND2, 4.6% in cyt b) que la interespecíficas (0.1-1.2%), lo que indicaba que una efectiva barrera existió en el pasado separando las dos especies. También estos autores mencionan que parece haber una zona de simpatría en Panamá.
Recomendaciones: Teniendo en cuenta que ambos tipos de análisis evolutivos (morfológico y molecular) indican que ambos taxas son especies diferentes y que aparentemente habría una zona de simpatría en Panamá, yo voto SI a esta propuesta.
Cracraft, J. & Prum, R.O. (1988) Patterns and processes of diversification: speciation and historical congruence in some Neotropical birds. Evolution, 42, 603-620.
Ribas C. C., Gaban-Lima, R., Miyaki, C. Y. y Cracraft, J. 2005. Historical biogeography and diversification within the Neotropical parrot genus Pionopsitta (Aves: Psittacidae). J. Biogeogr. 32:1409-1427.
Manuel Nores, May 2008
Comments from Remsen: "NO. Data published so far are insufficient to elevate coccinicollaris to species rank. If there is true sympatry, then this would be indisputable evidence for species rank. I consider the published evidence for this inadequate until all the details are published. First, the differences in plumage between these two taxa are really very small. The illustration in HBW shows them to be essentially identical except for an increase in reddish pigment in the neck area of coccinicollaris. Our one specimen of this form (one of the three specimens used by Ribas et al.) does not show nearly as much red as is indicated by the illustration in HBW, and descriptions of coccinicollaris imply that the degree of red is variable (although Wetmore [1968, birds of Panama book] suggested that much of this is sex-based). Wetmore (1968), who probably had the world's largest series of specimens from Panama to examine at USNM, did not note any sympatry and in fact stated: 'Apparently intergrades with the race coccinicollaris on the Caribbean slope in northern Coclé and western Colón.'
"I am especially wary of any taxonomic decision in New World parrots based only on distribution of red pigment. As those who have worked with Aratinga, Pyrrhura, Pionus, and other genera know, individual variation in expression of reddish pigmentation is substantial; some of that variation may be due to gene flow from adjacent populations or age/sex variation, but individual variation also appears substantial. In fact, in Pyrilia haematotis, of our 20 LSUMZ specimens from Costa Rica to Mexico, three show conspicuous red feathers in the belly to varying degrees and a fourth has a hint of reddish coloration there. None has any hint of reddish in the neck, as in coccinicollaris, but the point is that in the sister taxon, red pigmentation shows apparent individual variation. With the only known difference phenotypic between coccinicollaris and haematotis a variable amount of splotchy red in the neck (note that it is not a solid, discrete patch of color), we are on safe ground to require a more detailed analysis of the geographic and individual distribution of phenotypic traits in Panama. I cannot think of a single case of two parrot taxa that are ranked as species by any definition because they are parapatric or sympatric without gene flow that differ only by the presence/absence of a variable extent of reddish feathering.
"Ribas et al.'s (2005) evidence is as follows:
'These species occur in southern and northern Central America and there seems to exist a region of sympatry in Panama. In the present study, one of the sampled G. coccinicollaris individuals (number 27) is from a locality that is closer to those of the two G. haematotis specimens from Veraguas than it is to the other two G. coccinicollaris collected in Darien Province (see Fig. 1). Despite the geographical proximity and phenotypic similarity between these two species, interspecific distances were markedly higher (2.6% in ND2, 4.6% in cyt b) than the intraspecific distances (0.1-1.2%), indicating the existence of an effective barrier separating these two species in the past. such as vicariance events, are limited.'
"That the two forms are that close but still show substantial % sequence divergence is indeed of interest and points to the need for further research. The within-genus comparative % sequence data are also of interest but I think that many workers would not try to use them directly in taxonomic assessments. Note that the authors claim a "region of sympatry" but that their data show only allopatry, and not even parapatry.
"However, contrary to the statement of Ribas et al., these data in themselves provide absolutely no evidence of sympatry. Veraguas and Colón [where their #27 is from] are adjacent provinces, and the localities sampled are on opposite sides of the very region proposed as a zone of intergradation by Wetmore (1968). Worse, their locality for haematotis, "Cascajilloso," is presumably El Cascajilloso, which is in extreme southern Veraguas on the Azuero Peninsula on the Pacific slope, rather than on the Atlantic slope from whence the coccinicollaris specimen came from:
Therefore, more than straight-line geography may be involved in the separation of these localities. If a more comprehensive analysis of specimen localities not included in their tissue sampling shows sympatry, this in itself is worth publishing."
Comments from Stotz: "NO. In the absence of good data indicating sympatry, I agree with Van that the morphological differences are not typically those that suggest distinctive species. It may be that eventually we would split these, but it seems premature at best currently."
Comments from Jaramillo: "NO - This may be a good cryptic species, and hopefully Ribas et al are continuing to obtain more information on this question. If one taxon had a bright red head and the other didn't, that would make me feel more at ease with separating these species. However, given that the morphological difference is not there, something else - voice, behavior, display - something would need to be there as evidence that we have two biological species involved. It may be premature to make the split."
Comments from Cadena: "NO. The argument seemed sensible at first, but Van has now convinced me that definitive evidence for sympatry is not all that clear, and that because the morphological differences might not be as clear cut, it is best to wait for more detailed analyses."
Comments from Robbins: "NO. Van's comments illustrate the shortcomings of current data."
Comments from Pacheco: "NO. A análise de Van acerca do caso demonstra com clareza que as informações disponíveis não são congruentes com a proposta."