Baby penguin at aquarium growing quickly

Penguins' Rock at the Tennessee Aquarium is looking an awful lot like a nursery.

Twelve birds may be parents by the end of the summer, and there could be as many as seven or eight baby penguins before the breeding season is complete, aquarium officials say.

Already, two macaroni penguins -- Chaos and Paulie -- have produced offspring, and that baby bird is growing quickly, said Amy Graves, the aquarium's senior aviculturist.

"So far, everything with the baby penguin has been going really ideally," Ms. Graves said. "It's the best scenario we could hope for."

Three other pairs of birds are incubating eggs, she said, and a fourth set of penguins appears to be rushing to prepare a nest this week.

Aquarium officials are quick to point out that the odds are stacked against live births and survival of all the hatchlings. Just Monday, gentoo penguins Biscuit and Blue crushed their only egg. Ms. Graves said the egg was not fertilized, and the birds' instincts led them to dispose of it, which isn't unusual.

But Chaos and Paulie's chick is gaining weight steadily, she said, and the chick has begun waddling around a makeshift playpen erected in the exhibit.

Ms. Graves and other aquarium workers erected the same sort of acrylic barrier around the nest belonging to gentoos Bug and Big T.

That egg may hatch sometime this week, said Thom Benson, the aquarium's spokesman.

All the speculation about future live births might make aquarium visitors wonder how Penguins' Rock can support that many occupants. Guests have asked since the exhibit's 2007 opening whether it was big enough for the 19 birds that live there. Now, counting the newly hatched penguin, the exhibit is home to 20 birds.

"In the wild, penguins are communal animals," Mr. Benson said. "They could have a whole island, but they would only occupy a small part of it."

The Tennessee Aquarium is rated to house about 30 birds without any trouble, Ms. Graves said. But even though the facility could house all its offspring, she doubts the new births this year will stay at the facility long term.

All the penguins on display are on long-term or permanent loan from Sea World San Antonio, and that facility and the Association of Zoos and Aquariums will govern where the offspring of the loaned birds will reside, she said.

"When the birds reach sexual maturity, we will likely share them with other facilities," Ms. Graves said. "That will help keep the species going in captivity."

Sending the birds away from Chattanooga before they begin mating will ensure they won't breed with relatives, and it will ensure that other aquariums won't have to capture birds from the wild to keep their captive stocks going, she said.

That won't prevent the aquarium from naming any offspring or treating them like permanent residents of Penguins' Rock.

Ms. Graves said most zoologists consider birds "out of the woods" in terms of survival when they reach the 30-day mark. That's when Tennessee Aquarium personnel will think about naming its new chick, she said.

Roughly 60 days after a penguin hatches -- about Aug. 18 -- the bird should be able to swim on its own, she said.