Proposal (918) to South American Classification Committee

Merge Ciccaba into Strix

Background: As Van has indicated in SACC notes (Remsen et al. 2021, footnote 15a) under Ciccaba virgata, many authors over the past few decades have merged Ciccaba into Strix. However, as Van noted, there has not been concrete data to make this merger even though morphological data supporting recognition of Ciccaba has been weak at best (Peters 1938).

Recent molecular data demonstrate that Ciccaba virgata is deeply embedded within Strix (Salter et al. 2020, fig. 2). Although the designation of the type of Ciccaba is somewhat convoluted and confusing (Peters 1938), C. huhula is the type. Unfortunately, huhula was not included in the Salter et al. study. Nonetheless, given the plumage similarity among Ciccaba, and has been recognized for a long time, vocalizations (song and calls) among the four species that are currently in Ciccaba are very similar (e.g., compare huhula with virgata). Moreover, vocalizations of those four taxa are also similar to taxa that SACC recognizes as Strix, e.g., S. rufipes.

Recommendation: Given the above I recommend that Ciccaba finally be officially merged into Strix.

References:

Peters, J. L. 1938. Systematic position of the genus Ciccaba Wagler. Auk 55:179-186.

Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version: 9 February 2021. A classification of the bird species of South America. American Ornithological Society. http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm

Salter, J.F., C.H. Oliveros, P.A. Hosner, J.D. Manthey, M.B. Robbins, R.G. Moyle, R.T. Brumfield, B.C. Faircloth. 2020. Extensive paraphyly in the typical owl family (Strigidae). Ornithological Advances 137:1-15.

Mark Robbins, August 2021

Comments from Remsen: “YES. Genetic data confirm what has long been suspected, and this merger is mandated by those data. Nonetheless, until the type species huhula is included in a genetic analysis, we are gambling that virgata, the representative of the genus used by Salter et al., is more closely related to the other three Ciccaba than it is to Strix rufipes, the sister to C. virgata in Salter et al. Given the signal in the other data (voice and morphology), I suppose we can regard this as a safe gamble. What if better taxon-sampling showed that huhula + nigrolineata were sister to all other species? Would we be comfortable with treating them all as congeneric? Probably.”

Comments from Lane: “Reluctantly, YES. I do like the nice, tidy group of Ciccaba, but I suppose one can't argue with the phylogenetic placement.”

Comments from Stiles: “YES to merging Ciccaba under Strix; the morphological evidence is strong, and finally there is good genetic evidence as well for congeneric treatment.”

Comments from Areta: “YES. Not so much due to the genetic data in Salter et al. (2020), but rather because support for Ciccaba as a separate genus is weak and vocalizations of these owls suggest a close affinity.”

Comments from Pacheco: “YES. Recent genetic data provide objective data for the subordination of this group in Strix.”

Comments from Claramunt: “YES.”

Comments from Jaramillo: “YES – This seems solid, even though the type of Ciccaba is not sampled.”