Fig. 1
From: Comparing vocal structures of the parasitic and nonparasitic groups in Cuculinae
Spectrograms of brood parasitic and nonparasitic species illustrating five parameters measured in this study. a Cuculus canorus and b Chrysococcyx caprius as brood parasitic species. Likewise, c Coccyzus minuta and d Coccyzus americanus as nonparasitic species. HF, LF, DF, DT and NN represent high frequency, low frequency, delta frequency, delta time, and the number of notes, respectively. The number of black dots above spectrograms indicates the number of notes