Shedd's rockhopper penguin baby is a boy

The gender of the Shedd Aquarium’s newest addition, a rockhopper penguin that hatched in June, has been determined and it’s a boy.

Animal care staff confirmed that Chick No. 23, as he is still known, is a male through a genetic test conducted during a recent check-up, according to a statement from the aquarium. There are no observable sex differences in rockhopper penguins.

The chick hatched June 9, and has already nearly reached his full adult height of about 18 inches, according to the aquarium staff. He currently weighs about 4.5 pounds, up from 2 ounces when he hatched.

The chick has been exploring his habitat on his own, learning to swim by himself, and accepting foot from trainers after being fully weaned from his parents. He will be named at a later date.

Rockhopper penguins are considered a vulnerable species. The Shedd is currently home to more than 30 and has been part of a breeding program since 1991.

The chick is currently on display in the Polar Play Zone.

• It’s a boy! Born June 9, Chick #23 – the 23rd rockhopper penguin to be born at Shedd – currently weighs about 4.5 pounds and has nearly reached full adult height of about one-and-a-half feet. | ©Shedd Aquarium/Brenna Hernandez

• As Shedd Aquarium’s three-month-old rockhopper penguin chick is quickly reaching new milestones, animal care staff has confirmed that the newest addition at the aquarium is a male. | ©Shedd Aquarium/Brenna Hernandez