Part 1 of 2. The Season 34 premiere focuses on the work of human caretakers of orphaned baby animals. At Australia's Cape Otway Conservation Centre, the staff cares for a baby koala found along a road. It's weak and underweight, and should be spending its first six months inside its mother's pouch; the staff gives it a teddy bear to hold for comfort. At a sanctuary in Costa Rica, meanwhile, primatologist Sam Trull cares for six baby orphan sloths, including one that has pneumonia.

Growing up in the wild is hard enough on young animals when they have parents to rely on for protection and guidance, but what happens when they lose their parents? How do they survive? Over the past few years, great strides have been made in understanding how to rescue and rehabilitate orphaned wildlife.