Geranoaetus (1 Viewer)

[Richard Klim]

Amaral, Sheldon, Gamauf, Haring, Riesing, Silveira & Wajntal 2010. Priority of Geranoaetus Kaup, 1844 over Tachytriorchis Kaup, 1844 (Aves: Accipitridae) based on the first reviser principle. Zootaxa 2534: 67-68.
http://www.mapress.com/zootaxa/2010/f/z02534p068f.pdf

Richard

 

[Peter Kovalik]

José Cabot-Nieves, Tjitte de Vries, and Sergio Alvarado. 2021. The unification of the Variable Buzzard (Geranoaetus polyosoma) and Gurney’s Buzzard (Geranoaetus poecilochrous) is unjustified: comments on Farquhar’s proposal of conspecificity. Revista Chilena de Ornitología 26: 89-95.

ABSTRACT.- Farquhar (1998) proposed the unification of the Variable Buzzard (Geranoaetus polyosoma) and Gurney’s Buzzard (G. poecilochrous) into the first species because he did not find morphological and vocal differences that would guarantee their status as separate species. We reviewed the work of Farquhar (1998) and we detected that the author did not separate specimens from each species by simple sight nor did he use the Stresemann (1925) criterion correctly to identify them. The author treated body measurements and plumage descriptions, respectively heterogeneous, as if they were homogeneous samples. Analyzes by Farquhar, which included mis-sexed birds, are misleading as they do not allow for characterizing species based on their respective body proportions and plumage patterns. Furthermore, the author did not consider that the polymorphism of both species is due to sexual dimorphism, the existence of pale- and dark-morphs, and the late maturation of the plumage. The author’s interpretation of alarm calls was subjective. These observations weaken the proposal to unify the Variable and Gurney’s Buzzard into a single species. Therefore we propose that they continue to be considered separate species.

pdf: https://aveschile.cl/wp-content/upl...es_et_al-variable-buzzard-vs-puna-buzzard.pdf

 

[pbjosh]

Seems interesting to publish a paper on these birds using common names that aren't in contemporary use anywhere in the hemisphere where the birds occur, to the best of my knowledge. I've never heard of a Variable Buzzard nor of a Gurney's Buzzard, and I've spent ~6 years living and birding through the range and have almost every modern guidebook that would make mention of them... bit of a headscratcher?

Google says:
Variable Hawk: 200k results
Red-backed Hawk: 220k results
Puna Hawk: 4400 results

Variable Buzzard: 7000 results but almost none of them have anything to do with the bird in question, other than a link to the above paper
Gurney's Buzzard: 550 results

 

[l_raty]

Variable Buzzard: 7000 results but almost none of them have anything to do with the bird in question, other than a link to the above paper

I'd expect most hits to be things like "Buse variable - Buzzard", where "Buse variable" and "Buzzard" are respectively a French and an English name for Buteo buteo...

 

[Jim LeNomenclatoriste]

Buzzard, Buzzard. You said Buzzard ? How Buzzard ! 😏

 

[Peter Kovalik]

Cabot-Nieves, José, Tjitte de Vries, and Sergio Alvarado Orellana (2022) Wing-shape and alarm call differences between Gurney's Buzzard (Geranoaetus poecilochrous) and Variable Buzzard (Geranoaetus polyosoma) corroborates that they are seperates [sic] species. Revista Chilena de Ornotologia 28: 28-38.
https://aveschile.cl/wp-content/upl...etween-Gurneys-Buzzard-Variable-Buzzard-3.pdf


ABSTRACT
To discriminate between the Gurney’s Buzzard (Geranoaetus poecilochrous) and the Variable Buzzard (G. polyosoma), we compared their wing shapes and the sonograms of their alarm calls. We obtained the measurements from 98 Gurney’s Buzzard skins and 349 Variable Buzzard skins from different museums and live birds in captivity (14 Gurney’s Buzzards and 20 Variable Buzzards). The Gurney’s Buzzard had proportionally higher wing length values and lower wing formula values than the latter. In addition, the former had proportionally greater wing depth, shorter wing tip length, less wing aspect, and blunter wingtip. The pattern of wing length was geographically opposite between the two species. Gurney’s Buzzards were larger winged in the north and smaller winged in the south of their range, while the opposite was true for Variable Buzzards. The results of the comparative analysis of sonograms showed that the alarm calls of the Gurney’s Buzzard are longer, with fewer notes than those of the Variable Buzzard. Based on this evidence, we recommend treating these taxa as distinct species.