BOSTON -- Like many moms of newborns, Caitlin Hume still has plenty of work to do when she gets home. There's the herring-and-krill formula to prepare, followed by a little peeping and playtime, then bed.
For the past few weeks, Hume and fellow New England Aquarium biologist Heather Urquhart have been mothering a 22-ounce Little Blue Penguin that was rejected by its parents after a difficult hatching.
Each night, the two surrogate moms delicately pack the baby -- covered in soft, gray-blue down -- into a plastic cooler. Inside, the bird rests comfortably, swaddled in a white towel for the car ride home, oblivious to Boston's rush-hour traffic.
Once home, the still-unnamed chick waits in the guest room until Hume prepares a baby formula of herring fillet and shrimplike krill that goes into a blender and is heated to about 98 degrees. The pungent meal, resembling a chocolate shake, is fed to the penguin four times a day using a syringe with a special tip.
After dinner, the penguin enjoys a long nap -- not unlike a human baby.
"After you feed him, he'll make some peeping noises for a while, and then he goes to sleep," said Hume, who has no children of her own. "And then he's out cold until the next feeding" around 5 a.m.
The Little Blue Penguin species, which is native to Australia and New Zealand, is among three that are part of the New England Aquarium's penguin habitat. The other two are the African, native to South Africa, and the Rockhopper, which is found principally along Argentina and the Falkland Islands.
Andrea Desjardins, a penguin biologist who works at the aquarium, said the penguin team noticed an egg was about a week overdue from its normal 38-day term. They found the chick inside was still developing, so they essentially induced the chick to hatch by slowly chipping away tiny bits of shell, allowing the penguin to eventually break through.
When the biologists tried to give the bird back to his parents to raise it normally, they rejected the baby.
"Unfortunately being separated from the egg so long, the parents seemed uninterested in the chick," Desjardins said.
Aquarium biologists said the baby could have died because it wasn't being kept warm or fed. That's when the surrogate moms stepped in.
"It's a lot of work, although I guess it's probably easier than having a real baby because I can leave him in my house when I'm done," Hume said.
During the day, the penguin is cared for deep inside the aquarium, away from visitors.
The baby penguin appears to be making good progress and likely will be introduced to other chicks by the end of May. Biologists won't be able to determine the bird's sex until it is 3 months old.
Urquhart, who manages the penguin exhibit, admits to a little separation anxiety when it's Hume's turn to take the chick home. When the baby is with her, Urquart said she will sometimes wake up in the middle of the night just to check on it.
She has been involved in home-caring for animals since she came to the aquarium 20 years ago.
"It creates a special feeling for you. You feel like you're part of a very special process," Urquhart said. "You're helping bring a new life into the world."