Here’s a brief but informative video that presents facts about female rhinos’ gestation periods, rhino births, and the lives of newborn calves. Video description reads:
Every two and a half to five years, a female rhino will reproduce. Female rhinos carry their young for a gestation period of 15 to 16 months. They usually only have one baby at a time, though they do sometimes have twins. At birth, baby rhinos, which are called calves, are still quite big, at 88 to 140 lbs. (40 to 64 kg).
At around 3 years old, the calf will set out on its own. A rhino can live up to 45 years.