Table 1 Descriptions of echolocation acoustic parameters used as variables in species differentiation analyses and classification models. All parameters outlined here were used for the standard Random Forests classification model and BANTER’s first stage call classifier. Variable codes marked with an asterisk (*) indicate which acoustic parameters were used for multivariate differentiation analyses. A full list and the process used by the PAMpal package⁶¹ for calculating click parameters can be found in the R package documentation⁶⁵.

peak*

Peak frequency

kHz

Frequency value with the highest dB level

peak2*

Second peak frequency

kHz

Frequency value with the second highest dB level

peak3*

Third peak frequency

kHz

Frequency value with the third highest dB level

trough*

Frequency trough

kHz

Frequency value between peak and peak2 with the lowest dB value; also called spectral notch

trough2*

Second frequency trough

kHz

Frequency value between peak2 and peak3 with the lowest dB value

peakToPeak2*

First peak to second peak

kHz

Difference between the frequency values of peak and peak2

peakToPeak3*

First peak to third peak

kHz

Difference between the frequency values of peak and peak3

peak2ToPeak3*

Second peak to third peak

kHz

Difference between the frequency values of peak2 and peak3

Q_10dB

− 10 dB resonant quality factor

kHz

Metric of frequency pureness at − 10 dB calculated by dividing the center frequency by the bandwidth

Q_3dB*

− 3 dB resonant quality factor

kHz

Metric of frequency pureness at − 3 dB calculated by dividing the center frequency by the bandwidth

fmin_10dB

− 10 dB frequency minimum

kHz

− 10 dB frequency minimum

fmin_3dB*

− 3 dB frequency minimum

kHz

− 3 dB frequency minimum

fmax_10dB

− 10 dB frequency maximum

kHz

− 10 dB frequency maximum

fmax_3dB*

− 3 dB frequency maximum

kHz

− 3 dB frequency maximum

BW_10dB

− 10 dB bandwidth

kHz

− 10 dB bandwidth

BW_3dB*

− 3 dB bandwidth

kHz

− 3 dB bandwidth

centerHz_10dB

− 10 dB center frequency

kHz

[min frequency + (max frequency − min frequency)]/2 at − 10 dB

centerHz_3dB*

− 3 dB center frequency

kHz

[min frequency + (max frequency − min frequency)]/2 at − 3 dB

duration*

Click duration

µs

Time defined by the number of samples above 100 times the 40th percentile of the Teager Kaiser energy level

ici*

Inter-click interval

s

Time interval between consecutive clicks; mode approximated for each event