Table 1. Description of call parameters used in the statistical analysis of distress vocalization during squeezing (S-calls) and during isolation (I-calls).

Acoustic parameters	Description	Included in the statistical analysis
		S-calls	I-calls
Duration [ms]	Time between onset and offset of call	Yes	Yes
DFA2 mean [Hz]	Mean value of the frequency at which the second quartile of global energy is reached across all time segments	Yes	Yes
DFA3 mean [Hz]	Mean value of the frequency at which the third quartile of global energy is reached across all time segments	Yes	Yes
PF max [Hz]	Maximum frequency of the frequencies with the highest amplitude across all time segments	Yes	Yes
PF mean [Hz]	Mean of the frequencies with the highest amplitude across all time segments	Yes	Yes
DFB1 start[Hz]	Start value of the first frequency in the call that contains more energy than a particular threshold across all time segments	Yes	Yes
DFB1 mean [Hz]	Mean value of the first frequency in the call that contains more energy than a particular threshold across all time segments	Yes	Yes
DFB1 mod [Hz]	Mean difference between original DFB course and an average course	Yes	No
F0 mean [Hz]	Mean value of the fundamental frequency across tonal time segments	No	Yes
Noisy parts [%]	Percent of time segments in which no harmonic structure can be detected	No	Yes