There are only between 400 and 500 Sumatran tigers left in the wild, along with around 65 in North American zoos, and the species is listed as critically endangered.
“All I can do is smile because the team has realized our goal of producing critically endangered tiger cubs," said Great Cats curator Craig Saffoe.
This is the first litter for the zoo's female tiger, Damai, who is four years old. The cubs were sired by the zoo’s male Sumatran tiger, 12-year-old Kavi. In zoos, Sumatran tigers can live up to 20 years, though their lifespan is around 15 years in the wild.
Damai and Kavi have mated several times since late last year, and in June, zookeepers noticed Damai began gaining weight and exhibiting new behaviors. Staff confirmed the pregnancy on June 21 and began to prepare for the cubs' arrival.
Damai and her cubs will be off exhibit for several weeks, though fans can watch them via webcam. The cubs, born at 6:15 p.m. and 8:23 p.m. Monday, each weigh about two pounds and haven't opened their eyes yet.
Zookeepers say the first-time mother is doing a great job grooming, feeding and entertaining the cubs. "Damai came to us as a young tiger herself, so it’s really special to see her become a great mom," Saffoe said.
The cubs, who have not yet been named, will have health exams and and vaccinations, then in a few weeks their eyes will open and they'll be more mobile. In the meantime, zoo visitors can still see Kavi in the Great Cats exhibit.