Sumatran Rhinoceros feeding calf (born April 2007) at the Cincinnati Zoo, both covered with mud.The world's most endangered rhino,it suffers from deforestation and poaching for its horn. In 2001,the Cincinnati Zoo breed and had born a Sumatran Rhino calf in captivity,the first in 100 years. Calf is said to weigh over 400 lbs.