It’s time to say goodbye to the National Zoo’s two male lion cubs.

Baruti and Aslan, who were born on September 22, 2010, to mom Nababiep and dad Luke, will soon be heading to a new home at the Calgary Zoo in Canada.

Over the past year-and-a-half, zoo visitors have been able to watch the playful brothers chase each other, swim in the moat and wrestle. The exact date for their departure isn’t clear, but it will probably be this summer. It’s not easy to relocate lions; they need to travel in a special vehicle, and they need a special permit to travel to Canada. (Think of it as a feline passport.)

Once Baruti and Aslan get settled in Canada, zookeepers there will pair them up with female lions in the hope that the Calgary Zoo can have wonderful lion cubs just as the National Zoo did.

While it’s sad to say goodbye to animals we’ve watched grow up, the good news is that the zoo will continue to be home to male lions Luke and John and females Nababiep, Shera, Fahari, Zuri, Lelie and Lusaka.