Bella, a 9-year-old dolphin at Six Flags Discovery Kingdom in Vallejo, gave birth last week to her first calf. The pair are surprising researchers and trainers as they communicate with each other.
In her third trimester of pregnancy, Bella began emitting her "baby whistle" -- a unique call dolphins use to introduce themselves to each other. This behavior has never been observed before. Within minutes of being born, Bella's daughter also began to vocalize -- the earliest response recorded to date.
Hear more of Bella and baby.