Bioacoustics of Scytalopus speluncae

Description of the holotype : Adult male (MNRJ 36652) ( Figs. 7 – 9 ), collected at Nova Friburgo, Rio de Janeiro, in September 1989 . Bill black; forehead, crown, occiput, nape, mantle, rump, upper tail coverts, wing coverts and dorsal surface of rectrices Blackish Neutral Gray (82); lores, auriculars, chin, throat, upper breast, abdomen, flanks, crural feathers, crissum, primary and secondary under wing coverts, under tail coverts, and ventral surface of rectrices Dark (83) to Blackish Neutral Gray (82). Tarsus and digits pale brown (label data). Exposed culmen, 11.7 mm ; tail, 41.0 mm; wing (chord), 50.2 mm ; body mass, 16.0 g. Description of the paratypes ( Fig. 10 ): Adult female (MNRJ 36653), collected at Nova Friburgo, Rio de Janeiro, in September 1989 . Maxilla black and mandible brown (label data); forehead Blackish Neutral Gray (82); crown, occiput, nape and mantle Blackish Neutral Gray, shaded Brownish Olive (29); rump, upper tail coverts and dorsal surface of rectrices Brownish Olive, fringed black; upper secondary coverts Brownish Olive with transverse subterminal black patch and an Army Brown (219B) apical area; primaries and secondaries Homogeneous Sepia (119); lores, auriculars, throat and upper breast Dark Neutral Gray (83); feathers of the flanks, crural feathers, crissum and under tail coverts brown with transverse black patches; tarsus and digits yellowish brown (label data). Exposed culmen, 11.7 mm ; tail, 40.5 mm ; wing (chord), 51.1 mm ; body mass, 15.8 g . Subadult female (MNRJ 36655): collected at Nova Friburgo, Rio de Janeiro, in September 1989 . Maxilla black and mandible brown (label data); forehead Blackish Neutral Gray; crown, occiput, nape, mantle and dorsal surface of rectrices Blackish Neutral Gray shaded Brownish Olive; upper tail coverts and rump brown with two transverse black patches; lesser secondary coverts Brownish Olive with a transverse subterminal black patch and an Army Brown apical area; primaries and secondaries Sepia with different degrees of black at their tips and, sometimes, tiny white notches; lores, auriculars, throat and upper breast Dark Neutral Gray; flanks, crural feathers, crissum and under tail coverts brown with transverse black patches; tarsus and digits yellowish brown (label data). Exposed culmen, 11.9 mm ; tail, 40.0 mm; wing (chord), 52.9 mm ; body mass, 15.0 g. Young female (MNRJ 36656): collected at Nova Friburgo, Rio de Janeiro, in September 1989 . Maxilla black and mandible brown (label data); forehead Blackish Neutral Gray shaded Brownish Olive; crown, occiput, nape, mantle and dorsal surface of rectrices Brownish Olive; rump and upper tail coverts brown with two transverse black patches; lesser secondary coverts Brownish Olive, similar to adult female, with a transverse subterminal black patch and an Army Brown apical area; primaries and secondaries Sepia; lores, auriculars, throat and upper breast Medium Neutral Gray (84); abdomen, flanks, crural feathers, crissum and under tail coverts Buff (124) with transverse black patches; tarsus and digits brown (label data). Exposed culmen, 12.2 mm ; tail, 41.0 mm; wing (chord), 48.8 mm ; body mass, 14.5 g . Morphometry : See Table 1 . Vocalizations : The song phrases are of very variable duration and consist of regular repetition of the same notes ( Fig. 11 ), whereas the mean duration of the intervals between the different notes is 0.15 seconds. Thus a bird sings approximately five notes per second. Each note lasts for a mean of 0.05 seconds, and first ascends before descending ( Fig. 12 ), although the overall frequency varies only between 2.6 and 2.8 kHz, and the dominant frequency between just 5.3 and 5.4 kHz. The alarm­call consists of a single monosyllabic note with a mean of 0.1 seconds duration, at 1.8 kHz, with the dominant frequency 3.7 kHz ( Fig. 13 ).

Description of the holotype ( Figs. 2 – 5 ): Adult specimen (ZISP 145251) with auriculars, throat and upper breast close to Medium Neutral Gray (84) but with a pale brown tint. Upperparts close to Dark Grayish Brown (20) or Vandyke Brown (121). It should be mentioned that the holotype is almost 180 years old, and thus the original color of the upper and under parts may have acquired a somewhat brownish tone (foxing). Most of the feathers of the abdomen, flanks, crural feathers and under tail coverts are damaged and have lost their structure and color, but there are still small remnants of Clay Color (123B) on one feather of the left thigh, and on three feathers on the right flank (ilia); upper tail coverts Clay Color fringed black. Description of the topotypes : Adult male (MNRJ 44019, Figs. 7 – 10 ); collected at São João del Rei, Minas Gerais, at the right bank of Rio das Mortes ( 21o04’16.8’’S , 44o20’19.4’’W ) in September 2005 . Mandible blackish with gray tomia; crown, occiput, nape, greater primary coverts, and mantle Dark Neutral Gray (83); rump, upper secondary coverts, and dorsal surface of rectrices Dark Brownish Olive (129); upper tail coverts Buff to Clay Color (124 – 123B) with transverse black marks; lores Light Neutral Gray (85) with small black spots at the tips of the feathers; auriculars, throat, upper breast, secondary and under primary coverts Light Neutral Gray (85); wrist coverts (tectrices propatagi ventrales) and abdomen whitish, bordered distally with Pale Neutral Gray (86); abdomen, flanks, crural feathers and under tail coverts Clay Color with transverse black marks, tarsus and digits Olive­Yellow (52). Exposed culmen, 10.0 mm; tail, 40.0 mm; wing (chord), 48.9 mm ; mass, 16.5g . Adult female (MNRJ 44018, Fig. 2 ); collected at São João del Rei, Minas Gerais, in September 2005 . Mandible blackish with gray tomia; forehead Dark Neutral Gray; occiput, nape and mantle; upper secondary coverts and greater primary coverts Dark Brownish Olive with varying degrees of black at their distal end; dorsal surface of rectrices Dark Brownish Olive; rump and upper tail coverts Clay Color with transverse black marks; lores Light Neutral Gray with small black marks at the tips of the feathers; auriculars, throat, upper breast light neutral gray; secondary under coverts, primary under coverts and wrist coverts (tectrices propatagi ventrales) Buff (124) with narrow black marks; abdomen whitish, distally bordered Pale Neutral Gray; flanks, crural feathers, crissum and under tail coverts Clay Color with transverse black marks; tarsus and digits Olive­Yellow (52). Exposed culmen, 10.7 mm ; tail, 40.0 mm; wing (chord), 44.3 mm ; mass, 13.5 g . Geographic variation : The four specimens analyzed by us from the northern end of the Espinhaço Range, in the Chapada Diamantina ( Fig. 1 ), are somewhat different from the topotypes. These specimens lack the whitish ventral area and could be confused with S. pachecoi ( Maurício 2005 ) from Misiones ( Argentina ), or Rio Grande do Sul and Santa Catarina ( Brazil ). The upperparts of these specimens are Dark Neutral Gray (83) and the underparts Medium Neutral Gray (84), with buff­marked black feathers on the thighs, flanks, and crissum. Morphometry : See Table 1 . Vocalizations : The song phrases are variable in their duration and, like those of S. notorius , consist of regular repetitions of the same notes ( Fig. 14 ). However, the mean time between notes is 0.38 seconds. Thus the bird typically sings just 2.5 notes per second. Each note is very brief, lasting on average just 0.03 seconds, and descending in overall frequency ( Fig. 15 ), whereas the fundamental frequency varies between 1.8 and 2.0 kHz, and the dominant frequency between 3.5 and 4.1 kHz. Like S. notorius , the alarm­call consists of a single monosyllabic note which lasts a mean of 0.07 seconds, with a fundamental frequency of 3.5 kHz and a dominant frequency of 5.7 kHz ( Fig. 16 ). The song of S. speluncae is easily distinguished from that of S. notorius by its pace, which is approximately half that of S. notorius (2.5 notes per second vs. 5.0 notes per second), whilst the modulation describes an ascent, then descent in S. notorius but solely descends in S. speluncae . On the other hand, the song of S. speluncae is indistinguishable from that of S. pachecoi by pace, as S. pachecoi delivers 2.7 notes per second ( Maurício 2005:13 ) and S. speluncae 2.5 notes per second, and both descend in frequency. The call of S. speluncae is also identical to the call described by Maurício (2005) for S. pachecoi . In relation to S. novacapitalis (based on Vielliard 1990 and Maurício 2005 ) both S. notorius and S. speluncae possess distinctive characters, as the song of S. novacapitalis consists on average of just 1.1 notes per second, which is considerably fewer than either S. notorius or S. speluncae , whereas the duration of each note lasts on average 0.1 seconds, as opposed to either S. speluncae or S. notorius , which never exceeded 0.05 seconds in any sample analyzed.