Table 1.

Variability in USV production per day and in total between groups.

	Ultrasonic vocalization quantity
	CD-1			FVB
	CV	x̄	SD	CV	x̄	SD
PD 4	75.4	150.1	113.1	57.3*	119.5	68.5
PD 8	77.9*	127.6	99.4	80.4	126.0	101.2
PD 12	53.9*	248.8	134.1	101.8	149.8	152.5
PD 16	146.7*	32.8	48.2	182.1	32.1	58.5
Total	91.6*	139.8	128.1	103.2	110.2	110.3

^*The values with lower variability between groups are bolded. CV, coefficient of variability; x̄, mean; SD, standard deviation.