Table 1 Values (mean ± SD) of the acoustic parameters of sharp squeaks, produced by 120 individual yellow steppe lemmings belonging to 12 age classes and one-way ANOVA results for the effect of age class on the acoustics

1–4

10

0.186 ± 0.058

1.44 ± 0.34

3.48 ± 0.43

1.74 ± 0.45

1.18 ± 0.31

2.30 ± 0.32

10.65 ± 1.09

5–8

10

0.153 ± 0.039

1.69 ± 0.39

3.09 ± 0.88

2.03 ± 0.59

1.47 ± 0.29

1.62 ± 0.76

7.59 ± 2.77

9–12

10

0.129 ± 0.022

1.24 ± 0.33

2.09 ± 0.12

1.66 ± 0.23

1.17 ± 0.29

0.92 ± 0.29

6.27 ± 2.43

13–16

10

0.120 ± 0.031

1.23 ± 0.27

1.99 ± 0.22

1.71 ± 0.25

1.14 ± 0.25

0.86 ± 0.22

6.97 ± 1.56

17–20

10

0.126 ± 0.027

1.19 ± 0.25

1.99 ± 0.15

1.68 ± 0.20

1.10 ± 0.24

0.89 ± 0.19

6.74 ± 1.16

21–24

10

0.129 ± 0.056

1.06 ± 0.32

2.09 ± 0.23

1.76 ± 0.27

0.98 ± 0.24

1.11 ± 0.32

6.28 ± 1.58

25–28

10

0.125 ± 0.023

1.06 ± 0.17

2.07 ± 0.22

1.63 ± 0.28

0.98 ± 0.16

1.09 ± 0.18

5.94 ± 1.59

29–32

10

0.122 ± 0.034

1.09 ± 0.26

1.96 ± 0.31

1.42 ± 0.23

0.96 ± 0.25

1.00 ± 0.17

6.00 ± 1.90

33–36

10

0.109 ± 0.046

1.01 ± 0.21

1.87 ± 0.20

1.33 ± 0.25

0.90 ± 0.19

0.98 ± 0.29

5.11 ± 1.91

37–40

10

0.129 ± 0.053

0.99 ± 0.12

1.90 ± 0.25

1.52 ± 0.25

0.94 ± 0.12

0.96 ± 0.16

5.94 ± 1.89

41–60

10

0.101 ± 0.029

1.03 ± 0.22

1.80 ± 0.19

1.46 ± 0.27

0.95 ± 0.19

0.86 ± 0.23

4.73 ± 2.21

Adults

10

0.156 ± 0.038

0.74 ± 0.18

1.49 ± 0.26

1.18 ± 0.19

0.67 ± 0.16

0.82 ± 0.13

5.82 ± 0.99

ANOVA

F_11,108 = 3.27, p < 0.001

F_11,108 = 8.21, p < 0.001

F_11,108 = 26.23, p < 0.001

F_11,108 = 5.37, p < 0.001

F_11,108 = 7.23, p < 0.001

F_11,108 = 18.66, p < 0.001

F_11,108 = 6.84, p < 0.001