FIGURE 9 in Molecular phylogenetics of the wrens and allies (Passeriformes: Certhioidea), with comments on the relationships of Ferminia

FIGURE 9. Comparison of song characteristics between Ferminia cerverai and Cistothorus palustris. Shown is the spectrogram of a single Ferminia song (seconds 1.93–4.28 of Xeno-Canto catalog number XC256894, recorded by Hans Matheve and reproduced with permission), compared to the spectrogram of a single C. palustris song (seconds 1.77–2.92 of Xeno-Canto catalog number XC386079, recorded by the author) with a similar repeated syllable. Both spectrograms were generated using the "spectro" function of the R package "Seewave" (Sueur et al., 2008; the C. palustris recording was also filtered from 0–1.1 kHz to remove low-frequency background noise).