CHICAGO (CBS) — Penguins at the Shedd Aquarium are making their mark in history.

Four Rockhopper penguins at Shedd Aquarium turn 30 this month. They are the first penguins to turn 30 at the aquarium, making them the longest-lived penguins in Shedd’s history.

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And to celebrate not only their birthday, but the major milestone, animal care staff threw the birds a party with birthday-themed frozen treats and enrichment.

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The birds named Drake, Magdalena, Pebbles and Wellington join some of the oldest penguins in human care across the country. The partied it up by slidding on their bellies across the ice and pecking at the frozen treats.

According to the Shedd, because the penguins receive regular veterinary care, have no predators to avoid and don’t have to hunt for food, the aquarium has several penguins in their upper 20s, which is already considered geriatric. On average, Rockhopper penguins’ lifespan in the wild is about 10-15 years, and in human care the average lifespan is 20-25 years old.

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Check out some photos from the celebration below:

©Shedd Aquarium/Brenna Hernandez

©Shedd Aquarium/Brenna Hernandez

©Shedd Aquarium/Brenna Hernandez

©Shedd Aquarium/Brenna Hernandez

©Shedd Aquarium/Brenna Hernandez