VIDEO: Baby Penguin Joins Colony, Takes A Swim At Maryland Zoo

BALTIMORE, MD — The Baltimore Zoo's penguin colony hit an adorable milestone as its 1,000th chick, Millie, fully joined the colony, zoo officials said. Millie's sister, Holly, and other chicks joined as well.

Millie and Holly passed their swimming lessons, according to the zoo, after recently molting into their juvenile plumage.

The African penguin is an endangered species. The Maryland Zoo's penguins have helped curb that problem, according to the zoo's website, by having a thousand chicks to help replenish the species' population as part of a species survival plan.

When Millie hatched in mid-February her birth marked the first time that any zoo or aquarium in North America had hatched 1,000 African penguin chicks, officials said. She was named by popular vote, after thousands casted their ballots. Millie is short for millennium, a word with roots in "thousand." Fitting.

Article images provided by Maryland Zoo