Proposal (145) to South American Classification Committee

Treat Heliothryx barroti as conspecific with H. aurita

This one should be relatively straightforward, as it involves simply endorsing the status quo. However, as suggestions to the contrary continue to appear and it is marked "proposal required", I decided to chip in with this one.

The trans-Andean Heliothryx barroti has been recognized as a species distinct from the cis-Andean H. aurita by virtually all recent (and not-so-recent) authors, including Cory (1918), Peters (1945), Meyer de Schauensee (1966), Hilty & Brown (1986), Sibley & Monroe (1990), Schuchmann (1999) and Ridgely & Greenfield (2001). Zimmer (1953) dissented in a review of the races of H. aurita, noting that the only trenchant difference between barroti and aurita is the violet crown of males of the former, "a difference paralleled in various other species of hummingbirds". Another difference that he noted as of questionable value is the dusky spotting of the throat of female aurita, which is suggested in the immature females (but not the adults, as far as I am aware) of barroti; he stated that "females of the two are often indistinguishable". Zimmer has a point, and many recent treatments carry the qualification that "barroti may be conspecific with aurita". However, Zimmer's statement should be placed in the context of his belief, with Hellmayr, that geographic representatives of common stocks should be considered conspecific -- which has often led to lumping of forms subsequently considered to be separate species. A comparable case in point is the present consensus that the trans-Andean, bright-crowned Thalurania colombica represents a species separate from dull-crowned, cis-Andean T. furcata (in spite of the fact that some eastern forms of the latter, far from the range of colombica, have more-or-less bright crowns and intergrade with adjacent dull-crowned forms). In the case of the two Heliothryx, no intermediate specimens are known, including from the area where their ranges approach most closely in Ecuador and where some other forms have crossed the Andes in the Zamora-Loja region. Although conceding the close relationship of aurita and barroti, it seems best to follow current practice and consider them as allospecies of a superspecies, as do AOU (1998) and Sibley & Monroe (1990). Hence, I recommend a NO vote on this proposal.

References

Cory (1918)

Peters (1945)

Meyer de Schauensee (1966)

Hilty & Brown 1986

Sibley & Monroe 1990

AOU 1998

Ridgely & Greenfield 2001

ZIMMER, J. 1953a. Studies of Peruvian birds, No. 63. The hummingbird genera Oreonympha, Schistes, Heliothryx, Loddigesia, Heliomaster, Rhodopis, Thaumastura, Calliphlox, Myrtis, Myrmia and Acestrura. American Museum Novitates 1604: 1-26.

Gary Stiles, December 2004

_____________________________________________________________________________________

Comments from Remsen: "NO. Insufficient new evidence to overturn status quo."

Comments from Silva: "NO. These taxa are disjunct and diagnosable. I think they should be regarded as distinct species until someone presents evidence to make them subspecies of one single biological species."

Comments from Robbins: "NO. Given that there is no new evidence to overturn the standard treatment, I vote "no" in treating Heliothryx barroti as conspecific with H. aurita."

Comments from Pacheco: "NO. O tratamento de barroti e auritus como aloespécies me parece acomodar plenamente a situação."

Comments from Nores: "NO; pienso que las diferencias morfológicas (especialmente la corona del macho) pueden ser específicas. Como en los casos anteriores, parece mejor esperar estudios que lo justifiquen."

Comments from Zimmer: "NO. The two are clearly close, but there is no new evidence to justify a change in the status quo."