Bioacoustics of Cacomantis sepulcralis

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 ).