Proposal (1061) to South American Classification Committee

Transfer Accipiter cooperii and Accipiter bicolor to the genus Astur

Effect on SACC

Transferring Accipiter cooperii and Accipiter bicolor to the genus Astur.

New Information

Building upon earlier molecular studies that lacked taxa and had more limited genetic data (Lerner and Mindell 2005, Mindell et al. 2018), Catanach et al. (2024) produced a phylogeny based on UCEs that represented almost all taxa (237 species!) within the Accipitridae. Germane to our Committee’s charge, this impressive study found that the genus Accipiter, which has been a catch all for taxa with similar morphology across the World, is not monophyletic. In particular to our focus, Accipiter cooperii and Accipiter bicolor are in a clade that does not include the type of Accipiter, the Old World Accipiter nisus (see accompanying tree from Catanach et al.).

New World Accipiter striatus is sister to nisus, so it remains in Accipiter. Because of the lack of UCE data, Accipiter poliogaster is being retained in Accipiter awaiting further sequencing (Catanach, pers. comm.). Catanach et al.’s more densely sampled phylogeny was congruent with earlier studies (Breman et al. 2013, Mindell et al. 2018) and they placed the above New World taxa in the genus Astur.

I strongly recommend this straightforward treatment of placing cooperii and bicolor in the genus Astur. I thank Therese Catanach for comments on this proposal.

Literature cited

Breman, F.C., K. Jordaens, G. Sonet et al. 2013. DNA barcoding and evolutionary relationships in Accipiter Brisson, 1760 (Aves, Falconiformes: Accipitridae) with a focus on African and Eurasian representatives. Journal of Ornithology 154:265-287.

Catanach, T.A., M.R. Halley and S. Pirro. 2024. Enigmas no longer: using ultraconserved elements to place several unusual hawk taxa and address the non-monophyly of the genus Accipiter (Accipitriformes: Accipitridae). Biological Journal of the Linnean Society 144 (2). https://doi.org/10.1093/biolinnean/blae028

Lerner, H.R. and D.P. Mindell. 2005. Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA. Molecular Phylogenetics and Evolution 37:327-346.

Mindell, D.P, J. Fuchs, J.A. Johnson. 2018. Phylogeny, taxonomy, and geographic diversity of diurnal raptors: Falconiformes, Accipitriformes, and Cathartiformes. In: Birds of Prey: Biology and Conservation in the XXI Century. Cham, Switzerland. Springer.

Mark Robbins, August 2025

Vote tracking chart: https://www.museum.lsu.edu/~Remsen/SACCPropChart1044+.htm

Comments from Remsen: “YES. The best genetic dataset so far shows that Accipiter must be dismembered unless we want to force Circus and others into it. An early Miocene origin for true Accipiter is within the range of most groups we label as genera. It’s interesting that the accipiter morphotype may have changed little from the Oligocene – very conservative morphological evolution in the lineage as a whole despite the “breakout” lineage Circus.”

Comments from Naka: “YES. Given the phylogenetic data provided, I am happy to transfer those two species into the genus Astur, thus solving the paraphyletic nature of Accipiter.”

Comments from Areta: “YES to Astur as circumscribed by Catanach et al. (2024). The question with poliogaster deserves further scrutiny, as it may deserve a separate genus, depending on the level of divergence and on a phenotypic analysis. Meanwhile, I am fine with keeping it in Accipiter, given its phylogenetic position.”

Comments from Zimmer: “YES. As stated in the Proposal, this seems to be a straightforward course of action for addressing the paraphyly of Accipiter when cooperii and bicolor are included. As Nacho alludes to, the question of how poliogaster shakes out with more sequencing will be most interesting.”

Comments from Lane: “YES. I hope that the placement of A. poliogaster can be settled relatively quickly!”

Comments from Stiles: “YES. The genetic data clearly favor this change, which also mirrors a considerable difference is size (which in turn could favor differences in hunting tactics, maneuverability in flight  and prey choice) of these two from those of the remaining species in Accipiter.

Comments from Fabio Raposo (guest voter): “"YES. I agree with the proposal, which is based on an impressive phylogenetic study."