Can you elaborate on this? Is this a San Diego Zoo requirement for loaning koalas to other zoos? I thought that most of the koalas outside of California were on loan from the San Diego Zoo colony. Does anyone know if this is the case? LA and San Francisco have independent groups from San Diego.
LA's public exhibit is completely outdoors. As snowleopard suggested I think that there are indoor night quarters, but these are off public exhibit.
San Diego has a few indoor exhibits, but most of the koalas are in outdoor yards.
San Francisco has outdoor yards and an indoor facility with one viewing area. There are times of the year when it is too cold for them outside, but much of the time they are outside.
Actually most of San Diego's koalas are kept off-exhibit in the indoor "koala barn" (located behind the indoor exhibits). Only a couple koalas are outdoors at any given time.