Bioacoustics of Sakesphoroides cristatus niedeguidonae

3.7.2 | Diagnosis Morphology: The new species is assigned to the genus Sakesphoroides based on its morphological diagnostic characters as described by Grantsau (2010) , and its sister relationship to Sakesphoroides cristatus . Males of Sakesphoroides niedeguidonae are similar in plumage to Sakesphoroides cristatus , but females differ from the former by distinct crown, back, and tail colours, (Table 1). Sakesphoroides niedeguidonae has an overall lighter (Amber) colour rather than Chestnut as S. cristatus . The back is olive brown in S. niedeguidonae , whereas that of S. cristatus is Cinnamon-Brown. The overall tail colour in S. niedeguidonae is darker than in S. cristatus , with the most conspicuous difference being the black and white barring, replaced in S. cristatus only by discreet dull brown and rufous bars and complete absence of white barring (Figure S1). Voice: The loudsong of S. niedeguidonae is slightly similar in general pattern to that of S. cristatus , but differs conspicuously by the shape of the first notes. While the loudsong of S. niedeguidonae has initial notes with an ascending–descending pattern of frequency modulation, looking visually like an inverted ‘U’ letter on sound spectrograms, that of S. cristatus has initial ascending notes reaching quickly a high frequency (~2300 Hz) and then descending to the maximum amplitude and continuing to descend further to a lower frequency (~580 Hz), which confers to it a sigmoid shape on spectrograms (Figure 2). Additionally, the loudsong of S. niedeguidonae differs from that of S. cristatus by a significantly greater number of notes, longer overall duration, and slower pace in total song (see Table 3). Female recordings present noticeable higher pitched songs than males (ML579640291; Macaulay Library of Natural Sounds, Cornell Laboratory of Ornithology, Ithaca).