Proposal (113) to South American Classification Committee
Remove Oncostoma cinereigulare from Hypothetical List to Main List
Effect on South American CL: This transfers a species from our Hypothetical List to the Main List.
Background: Our Hypothetical List currently reads as follows:
"Oncostoma cinereigulare Northern Bentbill: A specimen was reported from northern Colombia (Romero & Rodriguez 1965), but see Ridgely & Tudor (1994) for reasons to treat the record as hypothetical until the specimen is re-examined."
New information: The lone specimen for Colombia and S.A. is in our collection and in my opinion is unquestionably cinereigulare, a species I know well from many years in Costa Rica. Although the range disjunction is indeed worrisomely huge, and no further specimens or sightings have been made (perhaps in part because the area in question is "zona roja" as regards security), I have no reason to doubt the identification or the authenticity of the locality data and recommend restoring this species to the main list.
RIDGELY, R. S., AND G. TUDOR. 1994. The birds of South America, vol. 2. Univ. Texas Press, Austin.
ROMERO, Z. H., AND J. V. RODRIGUEZ. 1965. Lozania 31: 5-6.
Comments from Nores: "SI. Aunque nada conozco de esta especie conf’o en la experiencia de Gary Stiles."
Comments from Jaramillo: "YES _ A specimen exists and has been identified as such by folks who know what they are talking about (Gary Stiles et al), so I am comfortable adding this one to our main list."
Comments from Schulenberg: "I trust Gary's judgment on the identification of the specimen, which he has seen and the rest of us have not.
"At the same time, it's hard not to be curious about this record. The specimen comes from northwestern Antioquia, near Chigirodo (Romero and Rodriguez 1980 [not 1965], Hilty and Brown 1986). Is Oncostoma olivaceum known from the same locality? or what are the nearest reported olivaceum localities? Is there anything more to be added to the story at this stage, other than that the specimen exists?"
Comments from Zimmer: "NO. I am truly on the fence on this one. On the one hand, I trust Gary's identification. On the other, I have to question how this bird could come from the locality in question. Unless we are prepared to accept the idea of a vagrant bentbill, you really have to wonder about this record. How sure can we be that the locality data on the specimen are accurate? I would like to know more about the proximity of the nearest O. olivaceum populations. I always felt that field separation of the two species was fairly straightforward, but then again, except in west-central Panama, the two are separable on geography alone. There are assertions in the literature (Ridgely and Tudor 1994) that some olivaceum individuals have whitish underparts (and therefore, are more like cinereigulare). I haven't personally noted any such individuals, but Bob must have some basis for making this statement. I'd like to know a little more about this issue in particular. Until then, my inclination is to err on the side of caution and vote NO."
Comments from Silva: "Yes. I trust in Gary's identification, but it would be a challenge to evaluate the nature of this record."