Fig. 3
Female walrus reproductive patterns. A The mean (± 95% CI, solid black line) monthly serum progesterone (ng/ml) concentrations during pregnancy and false pregnancy. Diapause is proposed to occur from March to July. Initiation of embryonic growth is estimated to occur in August whereby mean progesterone concentrations drop significantly for false pregnant females. Significant differences in concentrations between pregnant and false pregnant females are noted (*). B Patterns of conceptions, births, and weight (Kg). The 95% CI for the mean monthly annual changes in weight are demonstrated by two parallel lines. Mean monthly weight in pregnant females that is significantly different from non-pregnant females is marked (*)