Cacomantis sepulcralis (S. Müller, 1843 )

Wu, Meng Yue, Schodde, Richard & Rheindt, Frank E., 2022, Integrating voice and phenotype in a revision of the brush cuckoo Cacomantis variolosus (Aves: Cuculidae) complex, Zootaxa 5091 (1), pp. 69-106 : 93

4.1 Cacomantis sepulcralis (S. Müller, 1843)

Range: Malay Peninsula, Greater Sundas, Sulu Archipelago, main Philippines and west Nusa Tenggara east to Sumba and Alor.

Diagnosis: elements of the main song sharply inflected ( Fig. 2 ), differing significantly from those of all other taxa except the resident aeruginosus populations in the Moluccas ( Figs. 2 , 3 ); basic morph of Sundaic morphotype (see 3.2.2(1) above); body medium-sized and tail proportionally long: wing c. 110–120 mm, tail/wing ratio 1.00–1.12 ( Table 2 ); barred females with dorsa clearly barred dusky on cinnamon, and ventral white barred clearly black with vestigial cinnamon wash; juveniles intermediate in depth of tones and density of markings. Although populations from Sundaland and the Philippines exhibit the greatest variation in song note pace, overlapping many other taxa, their song is characterized by elements of a generally shorter duration ( Fig. 4 ). On bioacoustic grounds, therefore, these populations form a clearly diagnosable taxon group within the complex.

Whether as a species or subspecies of variolosus sensu lato, sepulcralis has been recognized by all reviewers since Stresemann (1912) distinguished it from similar-looking but sympatric east Asian Cacomantis merulinus ( Table 1).

Figures

FIGURE 2. The seven element shapes found in the Cacomantis variolosus complex. Taxon names given represent the following geographic song types (see Results): sepulcralis—Sundaland and Philippines, virescens—Sulawesi and Sula, aeruginosus—resident Moluccas, variolosus—Australasia, blandus—Admiralty Islands, addendus—Solomon Islands.

FIGURE 3. Principal component analysis plot based on the four vocal parameters measured. The first principal component (PC1) chiefly differentiates addendus and virescens, while the second PC splits the sepulcralis group and variolosus group. The inferred Australian migrant variolosus individual (ML 168559) found on Flores, Nusa Tenggara, Indonesia, is denoted by an arrow.

FIGURE 4. Boxplots of vocal measurements. Explanation of variables: pacing—elements per second; element duration in seconds; changes in center frequency in Hertz. For further explanation of vocal parameters, see Methods.