Female rhinos have a long gestation period

Rhinos have one of the longest gestation periods in mammals. They give birth to their calf after 15 to 16 months. The reason? This extended period is likely because they carry a much larger baby that requires more time and energy to develop. A newborn rhino calf can weigh between 88 to 140 pounds. Typically, rhino babies stay with their mothers for up to three years.