Proposal (901) to South American Classification Committee


Establish English names for Forpus crassirostris and F. xanthopterygius



Background: In SACC proposal 873, it was determined to treat western Amazonian Forpus crassirostris as specifically distinct from F. xanthopterygius of eastern Brazil and Bolivia. Prior to that split these taxa had been considered conspecific as Blue-winged Parrotlet F. xanthopterygius.


The initial SACC proposal recommended the use of Large-billed Parrotlet for F. crassirostris and that the “more widely distributed” F. xanthopterygius retain the name Blue-winged Parrotlet. However, both of those English name proposals failed to reach the necessary threshold of votes required for passage.


In the discussion of the proposal, other English names were offered for each of the two species, but two of these were posted late in the deliberation process and may not have had enough airing for more rigorous consideration.


This proposal is intended to revive those alternative names in a formal fashion for reconsideration.




The choices of English names to consider are proposed here:


Forpus crassirostris:

1A Riparian Parrotlet

1B Large-billed Parrotlet


Forpus xanthopterygius:

2A Cobalt-rumped Parrotlet

2B Blue-winged Parrotlet



Here is an edited excerpt from Tom Schulenberg’s discussion which introduced Riparian Parrotlet for F. crassirostris:


“I vote NO on 'Large-billed' (crassirostris). 'Large-billed' just isn't a great name to begin with, given that the difference in bill size between nominate crassirostris and the other taxa is not large and or consistent in difference (as noted by Van: "crassirostris does not occupy discrete morphospace"). I wonder if anyone would accept something like 'Riparian Parrotlet' (similar to the case of Riparian Antbird Cercomacroides fuscicauda), in a nod to the fact that it occupies open, river edge habitats (and now, of course, a lot of second growth etc.). This habitat preference isn't unique in the genus, but ...


And here is an edited version of David Donsker’s discussion which introduced Cobalt-rumped Parrotlet for F. xanthopterygius:


“I’d favor changing the English name of F. xanthopterygius [from Blue-winged Parrotlet] to avoid the potential for confusion that Dan and Van have both expressed. “Blue-winged” Parrotlet is the well-established English name for both the western Amazonian crassirostris and the eastern Brazilian/Bolivian xanthopterygius.  This situation becomes even more confusing given the unsettled history of the scientific name applied to Blue-winged Parrotlet (sensu lato), which has bounced around between F. crassirostris and F. xanthopterygius over the mid to late 20th century.  But there is no other suitable historical English name for this form that I am aware of. I like Tom’s suggestion of Blue-rumped Parrotlet, but I don’t think it would be wise to use it given the association of that name with Mexican Parrotlet.  But perhaps a similarly constructed name would be appropriate. As such, I’d propose Cobalt-rumped Parrotlet.  "Cobalt" is a reasonable modifier for the shade of the dark blue rump of this species. This has been variously described as "rich blue" (Ridgely et al. 2016); ”violet-blue" (Forshaw & Knight 2010); "cobalt-blue" (Juniper & Parr 1998); and "azul-colbalto" (F. x. flavissimus) or "azul-violeta" (nominate xanthopterygius) (Grantsau 2010).”


Based on these comments and others earlier expressed by members of the committee I recommend that the committee vote YES for the choice of English names for these two species as follows:


1A. Riparian Parrotlet for Forpus crassirostris

2A. Cobalt-rumped Parrotlet for Forpus xanthopterygius.


If one of the second options, as recommended in the original proposal, 1B (Large-billed) or 2B (Blue-winged) is still preferred, please so indicate.


David Donsker, January 2021




Comments from Lane:

1: Maybe my North American bias is showing here, but I usually consider "riparian" to refer to a band of trees along a river course in otherwise unforested landscape (like a gallery forest in the tropics). I wonder if "Varzea Parrotlet" isn't more appropriate due to its inherent Amazonian connotation?


“2A: Cobalt-rumped Parrotlet seems about the best we can do here.”


Comments from Stiles: “YES to 1A and 2A. My conception of riparian differs somewhat from that of Dan: for me it implies river- or, more generally, wáter-edge vegetation, which could be anything from trees to lower growth (e.g., Heliconia, gramalote, etc.), whereas I think of Varzea as seasonally flooded forest extending well beyond the edge at low water.”


Comments from Schulenberg: “I vote in favor of 1A Riparian Parrotlet (Forpus crassirostris) and 2A Cobalt-rumped Parrotlet (Forpus xanthopterygius).


Comments from Zimmer: “YES” to 1A (Riparian Parrotlet for F. crassirostris) and 2A (Cobalt-rumped Parrotlet for F. xanthopterygius) for reasons stated in the proposal.  I understand Dan’s comments regarding the North American interpretation of “riparian”, but in a South American context, I think Gary’s conception of the term is more applicable, with “gallery forest” filling the conceptual space occupied in North America by “riparian”, as already noted by Dan.  “Riverine Parrotlet” also strikes me as more suitable than “Varzea Parrotlet” and might be more palatable than “Riparian Parrotlet” to those of us grappling with a North American bias, but I’m perfectly happy to stick with “Riparian” as the modifier.”


Comments from Remsen: “1A. YES, but barely, I don’t like using Riparian as a term for South American birds.  Technically, riparian need not apply to non-forested landscapes, but it just doesn’t sound right for Neotropical birds – but it’s already in use for Riparian Antbird (Cercomacra fuscicauda) without causing an uproar.  I think Kevin’s suggestion of Riverine to be better, although no South American bird has that name.  Varzea should be restricted to várzea forest obligates, in my opinion. NO on Large-billed – very misleading name, as noted in the original proposal comments, so why repeat the mistake and give it further credence by using it in the English name? 2A.  YES to Cobalt-rumped. NO on Blue-winged for reasons already expressed, i.e. that name applies to a different taxonomic concept.”