The Brookfield Zoo is celebrating the birth of a bottlenose dolphin, the second dolphin birth at the west suburban zoo in just five days.

Allie, a 27-year-old bottlenose dolphin, gave birth to a female calf around 2:45 a.m. on Tuesday, according to the Chicago Zoological Society.

On Dec. 12, the zoo welcomed another dolphin, a male bottlenose calf born to 9-year-old Allison.

Allie is an experienced mother and has raised two previous calves.

“We are thrilled with this birth, as well as with Allison’s calf,” said Rita Stacey, curator of marine mammals for the society. “It has been very rewarding and exciting for our marine mammal team.”

Allie is a protective mother, successfully nursing the calf and slipstreaming, which is when the newborn stays close to its mom’s dorsal fin, gliding as it rides on the mom’s pressure wave, the society said.

It hasn’t been easy for zoo staff this month. The zoo announced the death of a male dolphin calf on Dec. 5. The calf’s mother was a first-time mother, 11-year-old Noelani. Zoe staff said it appeared to be a normal birth, but a necropsy was being performed to determine the cause of death.

The zoological society has cared for bottlenose dolphins for 54 years.