Age-specific reproduction in female sea otters (Enhydra lutris) from south-central Alaska: analysis of reproductive tracts

Abstract

Sexual maturity was first attained at age 2. The proportion of sexually mature animals increased from 30% at age 2 to 100% at age 5. Annual reproductive rates increased from 22% af age 2 to 78% at age 5 and remained relatively stable (75-88%) through to age 15. The sex ratio (male:female) of 49 fetal sea otters was 18:37 and differed significantly from parity. Females younger than age 8 tended to produce more female fetuses, while older mothers did not. -from Authors