Table 1. Effect of age on USV in AFR pups.

a. USV number
Group      Age	Results of time comparison		Results of overall time comparison
	F(1,690)	P	F(4,690)	P
AFR    P1 vs.P3	2.43	0.1198	3.02	0.0173*
P1 vs.P7	5.02	0.0254 *
P1 vs.P8	9.45	0.0022 **
P1 vs.P14	0.38	0.5352
P3 vs.P7	0.47	0.4952
P3 vs.P8	2.33	0.1270
P3 vs.P14	0.88	0.3490
P7 vs.P8	0.72	0.3951
P7 vs.P14	2.62	0.1058
P8 vs.P14	6.04	0.0142 *
b. USV frequency
Group      Age	Results of time comparison		Results of overall time comparison
	F(1,690)	P	F(4,690)	P
AFR    P1 vs.P3	3.04	0.0821	3.53	0.0076**
P1 vs.P7	9.74	0.0019**
P1 vs.P8	5.49	0.0196*
P1 vs.P14	1.87	0.1724
P3 vs.P7	4.29	0.0388 *
P3 vs.P8	0.75	0.3878
P3 vs.P14	0.29	0.5900
P7 vs.P8	1.67	0.1968
P7 vs.P14	7.06	0.0082 **
P8 vs.P14	2.07	0.1507
c. USV duration
Group      Age	Results of time comparison		Results of overall time comparison
	F(1,690)	P		F(1,690)
AFR    P1 vs.P3	1.39	0.2394	1.60	0.1738
P1 vs.P7	2.33	0.1277
P1 vs.P8	4.94	0.0266*
P1 vs.P14	0.13	0.7175
P3 vs.P7	0.12	0.7283
P3 vs.P8	1.11	0.2921
P3 vs.P14	0.66	0.4151
P7 vs.P8	0.50	0.4783
P7 vs.P14	1.35	0.2452
P8 vs.P14	3.47	0.628

*P<0.05

** P<0.01