Shedd Aquarium welcomed a Rockhopper Penguin Chick on June 9, 2015. The chick hatched to parents Edward and Annie, following penguin-breeding season in March. The yet-to-be-named penguin weighed 57 grams at birth and came in at 200 grams at a recent weigh-in; full growth is expected after about two to three months. Until the aquarium decides on a name, the tiny bird is being referred to as “Chick #23”. 

Photo Credit: Brenna Hernandez /Shedd Aquarium ; Video Credit: Sam Cejtin /Shedd Aquarium

Chick #23 has been attempting to preen its soft, down-like plumage, which is one milestone Shedd’s animal care team looks for to assess the growth of the bird. While there are no observable sex differences in Rockhopper Penguins, a genetic test after one year of age will determine whether the chick is a boy or a girl.

Guests can try to spot Chick #23 in Shedd’s Polar Play Zone, where it’s currently in its nest with its parents. It will be another month or so before the chick begins to wander on its own.

Shedd Aquarium houses two types of penguins in the Polar Play Zone exhibit: Rockhoppers (Eudyptes chrysocome) and Magellanics (Spheniscus magellanicus). The Rockhopper is the smaller, yet more eccentric penguin of the two breeds.

Rockhopper Penguins are listed as “Vulnerable” on the IUCN Red List of Threatened Species. Since 1991, Shedd has been part of a successful penguin breeding program and has contributed to a variety of global rescue efforts. Chick #23 is one of more than 30 Rockhopper Penguins currently at Shedd.