1. Overview of river dolphin echolocation signals.
Overview of river dolphin echolocation signals. Pictures, waveforms and power spectra of representative echolocation clicks from the Ganges river dolphin (Platanista gangetica), baiji (Lipotes vexillifer), boto (Inia geoffrensis) and franciscana (Pontoporia blainvillei). Power spectra are calculated for the example waveforms with FFT sizes of 1024 and sample rates of 500 kHz for the Ganges river dolphin, boto and franciscana and  kHz for the baiji (signal was digitised from analogue recording). Note that the baiji click is from a data set, where this click had one of the lowest peak frequencies, suggesting a potential under-representation of high-frequency energy in the power spectrum shown compared with the mean for this species. Ganges river dolphin data: Jensen et al., 2013; baiji data: Akamatsu et al., 1998; boto data: present study; franciscana data: Melcón et al., Photo credits: Ganges river dolphin: E. and R. Mansur, WCS; baiji: Institute of Hydrobiology, Chinese Academy of Sciences; boto: Jorge Andrade; franciscana: Miguel Iniguez, WDC.
Michael Ladegaard et al. J Exp Biol 2015;218:
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