Fig. 2

Individual and sexual identity in the discomfort sonic calls of the northern birch mice. Spectrograms of one call per individual are given for the 4 female (F1–F6) and 7 male (M2–M19) subject northern birch mice, n indicates the number of calls. Red bars represent the actual values of correct classifying of the discomfort calls to sex and to individual with DFA. Yellow bars represent the random (chance) values of correct classifying of the discomfort calls to sex and to individual with DFA. Comparisons between the actual and random values (indicated with brackets above the bars) were done using the permutation test. Bars indicate averages, whiskers indicate SD. The spectrogram was created with Hamming window; 48 kHz sampling rate; FFT 1024 points; frame 50%; and overlap 87.5%. Original wav-files are available in Additional file 2