PHILADELPHIA ZOO (WPVI) --A big birthday celebration at the Philadelphia Zoo Thursday.
Louis the gorilla turned 17 years old Thursday.
There was a big birthday sign in his exhibit at the zoo.
Although Louis seemed a bit distracted, preferring instead to sample all of the birthday treats given to him, including a yam cake.
Louis has been part of the Philadelphia zoo family since 2004.
He's one of five lowland gorillas at the zoo, all of them considered critically endangered.