Megascops usta ( Sclater, 1858 )

Dantas, Sidnei M., Weckstein, Jason D., Bates, John, Oliveira, Joiciane N., Catanach, Therese A. & Aleixo, Alexandre, 2021, Multi-character taxonomic review, systematics, and biogeography of the Blackcapped / Tawny-bellied Screech Owl (Megascops atricapilla-M. watsonii) complex (Aves: Strigidae), Zootaxa 4949 (3), pp. 401-444 : 428

Megascops usta ( Sclater, 1858)

Variable Screech-Owl

corujinha-relógio (Portuguese)

Scops usta Sclater, 1858 (type not examined).

Pisorhina watsonii (Cassin, 1848) : Hellmayr (1907).

Otus watsonii (Cassin, 1848) : Hellmayr (1910).

Pisorhina usta ( Sclater, 1858) : Snethlage (1914).

Otus watsonii usta ( Sclater, 1858) : Chapman (1928); Peters (1940); Hekstra (1982); Marks et al. 1999; Weick (2006; part: specimens in southernmost Venezuela and Amazonian Colombia, Ecuador, Peru, Bolivia, and Brazil between the western banks of the Negro and the lower Tapajós and upper Xingu rivers).

Otus atricapillus morelius Hekstra, 1982 : Browning (1989); holotype at AMNH examined .

Otus atricapillus inambarii Hekstra, 1982 : Browning (1989); holotype at FMNH examined .

Otus atricapillus fulvescens Hekstra, 1982 : Browning (1989); holotype at AMNH examined .

Megascops usta ( Sclater, 1858) : König et al. (1999); König & Weick (2008; part: specimens in southernmost Venezuela and Amazonian Colombia, Ecuador, Peru, Bolivia, and Brazil between the western banks of the Negro and the lower Tapajós and upper Xingu rivers).

Megascops watsonii usta ( Sclater, 1858) : Dickinson & Remsen (2013); Clements et al. (2019); Gill et al. (2020; part: populations in southernmost Venezuela and Amazonian Colombia, Ecuador, Peru, Bolivia, and Brazil between the western banks of the Negro and the lower Tapajós and upper Xingu rivers).

With type locality referred as Tefé, Amazonas, Brazil ( Sclater, 1858), and corresponding to specimens in Clade B, M. usta is distributed over a wide geographic area in Amazonia, ranging from west of the Branco-Negro rivers throughout the Imerí, Napo, Inambari, Madeira and upper stretches of the Tapajos and Xingu AOEs. Strong statistical support for reciprocal monophyly, high degree of coalescence, and high uncorrected pairwise p-distances ranging from 2.1% ( M. ater ) to 6.4% ( M. watsonii ) differentiates this taxon from others in the Megascops atricapilla-M. watsonii complex. Morphologically variable with multiple morphs, mainly brown or red, but also gray, and not safely distinguishable solely based on morphology from the other species in the complex. There is geographical variation in the frequency of different morphs among populations. Apparently does not include morphs as dark in color as those found in M. watsonii and M. ater . Vocally distinct from M. watsonii , M. stangiae and M. atricapilla by on average slower-paced longsongs and shortsongs ( Fig. 9 ; Tables 6 , 8 , and 10).

Figures

FIGURE 9. Geographic variation in longsong paces (notes/s) across clades A–F in the Megascops atricapilla-M. watsonii complex. Locality codes are given as letters followed by numbers and can be found in full in the Appendix. Numbers next to locality dots represent locally measured longsong pace values. When more than one individual was sampled at a given locality, the total number of longsongs measured is given in parentheses, with reported values representing averages.