Israel's Ramat Gan Zoo welcomed a happy addition to its hippopotamus family this week with the birth of a 30 kg baby. The new hippo who has jokingly been named "Fatty" because of his weight, is one of 30 hippos at the Safari Zoo in central Israel. Zoo curator Amelia Turkel says the birth is one of many that have been born in the zoo and which has created "the largest herd in captivity". Once numerous in all African rivers and streams with deep water but with rivers and lakes drying up in the desert region the hippo is now largely restricted to natural parks. The dwindling number of hippos in Africa is also due to the ban on hunting elephants in Africa. Ramat Gan Zoo hopes to relocate some of its hippo herd to South Africa to help alleviate the problems. "We did contact an NGO (non-governmental organization) in South Africa that is concerned in bringing wild life back to Africa, especially species whose numbers have declined greatly and it turns out that hippos' numbers have declined," said Turkel. "Ivory and ivory-like substances are not available for carving. So actually there are good substitutes because the tusk of a hippo which is a tube, it's this long...is certainly a good item to be carved just as ivory is, so people have hunted hippos as a substitute for elephants," Turkel explained. A female hippopotamus gives birth to a single calf about 8 months after mating. Hippopotamus calves are born on land or in shallow water, and they mostly suckle milk from their mothers underwater. Due to their specific gravity, they can submerge themselves completely and walk on the bottom of the river. They come up on land to feed on grass and crops, mainly at night, and are most dangerous when they feels cut off from their watery environment. Hippos' weight averages between 1,100 and 1,400 kg and can weigh as much as 3,200 kg.