Lincoln Park Zoo celebrates baby gorilla born on Mother's Day

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Christopher Bijalba / Lincoln Park Zoo

Chicago's Lincoln Park Zoo is celebrating the Mother's Day birth of a newborn western lowland gorilla.

Zoo officials say the male infant was born at about 2 a.m. Sunday to mother Rollie and father Kwan, who weighs in at more than 400 pounds (180 kilograms). The newborn has no name. He'll make his public debut Wednesday when the zoo's Regenstein Center for African Apes reopens.

His weight is estimated at 4 to 5 pounds (1.8 to 2.3 kilograms). Zoo general curator Dave Bernier says officials feel he's "on a really good trajectory."

The baby is the second for 30-year-old Kwan and 22-year-old Rollie, who had Nayembi in 2012.

The pair's breeding was initiated on the recommendation of the inter-zoo Species Survival Plan, which manages the captive western lowland gorilla population.