The Minnesota Zoo unveiled 10 juvenile penguins on Friday that were hatched in November and December. The four males and six females are considered endangered, and are seen as significant achievements for the zoo, which opened the 3M Penguins of the African Coast exhibit in 2011.

The African penguins generally live and nest on the southwest coast of Africa, feeding primarily on anchovies, sardines, herring and pelagic goby. Like most other penguins, they are endangered in the wild due to oil spills, historical hunting and habitat destruction.

The penguins were raised behind-the-scenes, and grew very fast. They have already molted in their juvenile plumage, can swim well, and each are starting to develop their own personalities, the zoo says. The chicks were taught to eat from zookeepers, then reintroduced to adult penguins off exhibit, and have integrated well.