A western lowland gorilla at Atlanta's zoo is pregnant.

Zoo Atlanta says Lulu, who turned 13 Wednesday, is expecting an infant in the spring. Lulu's infant would be the 19th gorilla born at Zoo Atlanta since the opening of its rainforest exhibit in 1988.

The news of Lulu's pregnancy comes just after Ivan, one of the zoo's most cherished gorillas died earlier this week at the age of 50.

Western lowland gorillas are critically endangered, and their wild populations may have declined by as much as 95 percent in some parts of Africa over the past 20 years. The primary threats to wild populations are poaching and habitat loss.

Zoo Atlanta is home to North America's largest collection of western lowland gorillas.

Tags: Zoo Atlanta, Gorilla, Prenant, Lulu