TORONTO -- The Toronto Zoo says the two giant panda cubs born about six weeks ago are doing "very well" and have outgrown their incubator.
The zoo says the cubs have been moved to a larger incubator and alternate spending time with their mother, Er Shun, who is on loan from China.
It says Er Shun is feeding her cubs and staff have been increasing her bamboo intake to maintain her milk production. The zoo says the cubs' diet is being supplemented with formula.
Photos released by the zoo show the cubs have grown their trademark black-and-white fur.
Giant pandas are born blind and the cubs are pink with short, thin white fur. The cubs are about 1/900th of the size of their mother, making them among the smallest newborn mammals compared to their mother.
The zoo says it is still a critical time for the cubs and they remain in the maternity area of the panda exhibit, which is hidden to the public.
Staff have said the cubs, if they survive, will live at the zoo for about two years and will likely return to China once they are weaned from Er Shun.
Er Shun and a male panda named Da Mao arrived from China in 2013 and are slated to move to the Calgary Zoo in 2018.
