CHICAGO (CBS) — Memorial Day brought a new arrival to Chicago’s Shedd Aquarium.

WBBM Newsradio’s Regine Schlesinger reports a new baby Pacific white-sided dolphin was born at the Shedd on Monday.

Shedd spokeswoman Andrea Smalec said just after the mother, Piquet, gave birth, the new calf swam to the surface, took its first breath, and began swimming and bonding with its mother.

Aquarium staff aren’t sure yet if the calf is a male or female. It’s still very fragile. Most dolphin calves born in captivity don’t make it past their first year.

Aquarium staffers were worried Piquet might give birth to the calf during the weekend of the NATO Summit, so several workers moved into the aquarium that weekend just in case.

“Her starting window for the birth area was NATO weekend, moving through the first of June, so she hung out until Memorial Day, basically, for us,” Smalec said.

Smalec said the calf won’t be put on display until it’s stronger.

“Right now, the mother and calf cannot be seen by the public,” she said. “But our Oceanarium is still accessible, the underwater viewing, and to come see our other dolphins.”

The new calf is one of fewer than 20 Pacific white-sided dolphins in North American zoos and aquariums.