Age and Length at Sexual Maturity, Calving Interval, and Ovarian Activity of Female Tamanend's Bottlenose Dolphins (Tursiops erebennus) in South Carolina Waters

Tamanend's bottlenose dolphins (Tursiops erebennus) face population and environmental stressors that influence the age and length at sexual maturity (ASM and LSM, respectively) and calving interval, which are life history traits used to assess population status and health. We provide initial estimates of the ASM, LSM, and calving interval, as well as descriptions of ovarian activity of female Tamanend's bottlenose dolphins that stranded in South Carolina waters. ASM and LSM estimates were approximately 10 years and 215 cm, respectively. Analysis of carcasses sampled over a three-decade period (1992–2022) indicated temporal variations in maturation, possibly related to unusual mortality events and/or periods of poor animal health. Stranding location did not appear to influence maturation. The calving interval estimate averaged between 2 and 4 years. Corpora counts relevant to age supported previous findings of corpora accumulation in bottlenose dolphins. In mature females, the left ovary accumulated more corpora and generally weighed more than the right ovary, suggesting asymmetric ovarian activity. To support the conservation of this newly recognized coastal and estuarine species, we suggest continued monitoring of the onset of sexual maturation and calving interval.