The National Zoo has welcome two new additions to its Great Cats exhibit. Two Sumatran tiger cubs were born on August 5, according to a release, a major victory for conservation efforts.

The cubs were born to Damai, a female Sumatran tiger who came to the National Zoo from the San Diego Zoo Wild Animal Park in 2011, and Kavi, a male Sumatran tiger (duh) who arrived last year from Zoo Atlanta.

“It’s taken more than two years of perseverance getting to know Damai and Kavi and letting them get to know each other so that we could reach this celebratory moment,” Great Cats curator Craig Saffoe said in a release. “All I can do is smile because the team has realized our goal of producing critically endangered tiger cubs. Damai came to us as a young tiger herself, so it’s really special to see her become a great mom.”

As the Zoo points out in their release, Sumatran tigers are critically endangered, with only 400 to 500 left in the wild.

In case you were wondering why the only photos of the cubs released thus far are surveillance-style, the Zoo says its tiger keepers are giving Damai room and time to bond with her cubs. The cubs will likely not be on exhibit until the fall, the release notes. But Damai and the cubs can be observed through the Zoo’s Tiger Cub Cam.