There are a total of five species of rhinos that exist in the world. Two of these species are found in Africa and three of them are in Asia. Both of the African species have two horns and are either white or black in color. Asian rhinos which includes the Indian and the Javan species are distinctive as they posses just one horn while the Sumatran one has two. They are fairly huge with the white rhino considered to be the second largest land mammal next to the elephant. The five species range in weight from 750 pounds to 8,000 pounds and they stand anywhere from four and a half feet to six feet tall. Their habitat ranges from savannas to dense forests in tropical and subtropical regions. It is estimated that wild rhinos live up to 35 years and in captivity, they could live up to 40 years. Despite their fierce look, Rhinos are herbivores. White rhinos, with their square-shaped lips, are ideally suited to graze on grass. Other rhinos prefer to eat the foliage of trees or bushes. They are solitary creatures and both male and female rhinos establish territories. Males mark and defend their territories. Rhinos use their horns not only in battles for territory or females but also to defend themselves from lions, tigers and hyenas. Males and females frequently fight during courtship and this sometimes leading to serious wounds inflicted by their horns. After mating, the pair go their separate ways. A calf is born 14 to 18 months later. Although they nurse for a year, calves are able to begin eating vegetation one week after birth. Rhinocerous rank among the most endangered species on Earth and are usually subjected to poaching as they are extremely valued for their horns. Some cultures believe that the powdered rhino horn will cure everything from fever to food poisoning and will enhance sexual stamina.