Dhaka, June 8 -- Brookfield Zoo Chicago captured the remarkable moment a bottlenose dolphin gave birth early Saturday, assisted by another experienced dolphin, in a video released by zoo staff.

The 38-year-old dolphin, Allie, delivered her calf in the early hours as a team of veterinarians monitored the process. In the footage, voices cheer her on - "Push, push, push" - as the calf's tail emerges. Moments later, the baby dolphin wriggles free and instinctively swims to the surface for its first breath.

Accompanying Allie in the birthing pool was Tapeko, a 43-year-old dolphin who has previously given birth. She remained close throughout the hour-long labor and was seen guiding the newborn to the surface immediately after birth.

Accordin...