Table 4 Reproductive maturity and pregnancy outcome for captive female Pacific walruses from 1980 through 2019

Reproductive parameter

Mean ± SD

Median (range)

Observations

 Age (y) at first ovulation

8.6 ± 2.4

7.8 (4.8 to 12.7)

12

 Age (y) at first conception

9.6 ± 2.5

8.9 (5.8 to 13.8)

9

 Weight (kg) at first conception

658 ± 111

649 (488 to 845)

6

 Age (y) at maximum weight (kg)

10.2 ± 0.9

11 (8 to 11)

5

 Percent of adult weight at first conception

0.95 ± 0.08

0.96 (0.76 to 1.1)

6

 Age (y) of all conceptions

14.7 ± 4.3

14.4 (5.9 to 28.5)

26

 Min false pregnancy length

231 ± 34

234 (169 to 293)

12

 Gestation length (d)

423 ± 13.4

425 (394 to 441)

11

 Calving Interval

2.6 ± 0.5

3 (2 to 3)

15

Reproductive event outcomes

Parameter

Total number (%)

% of Pregnancies

 False pregnancies

12 (31.6)

 Twins

4 (10.5)

15.4

 Abortion

1 (0.03)

3.8

 Stillbirth

4 (10.5)

15.4

 Live births

17 (44.7)

65.4

 Total Events

38 (100)