Figure 2

Measured variables for adult yellow steppe lemmings USV calls exemplified by a female USV without frequency jump and by a female USV with frequency jump. Spectrogram (right) and mean power spectrum of the first entire call (left). Designations: duration—call duration; f0beg—the fundamental frequency at the onset of a call; f0end—the fundamental frequency at the end of a call; f0max—the maximum fundamental frequency; f0min—the minimum fundamental frequency; fpeak—the frequency of maximum amplitude; q25—the lower quartile; q50—the medium quartile; q75—the upper quartile. Spectrogram was created using sampling frequency 192 kHz, Hamming window, FFT 1024 points, frame 50% and overlap 87.5%.