Pakistan is a populous, multi-ethnic country in South Asia. With a predominantly Indo-Iranian-speaking population, Pakistan is historically and culturally linked to its neighbors Iran, Afghanistan and India. Pakistan is the site of many ancient cultures, such as the 8,500-year-old Neolithic Mehrgarh site in Balochistan, the Indus Valley Civilization of the Bronze Age and the ancient Gandhara civilization. Pakistan has a diverse geography and climate and is host to a wide diversity of wildlife. There are around 668 species of birds in the country, including crows, sparrows, mynas, hawks, falcons and eagles. Many of the birds observed in Pakistan are migratory, arriving from Europe, Central Asia and India. In the southern plains lives mongooses, Small Indian Civets, hares, the Asiatic Jackal, the Indian Pangolin, the Jungle Cat and the Desert Cat. The Indus is home to Mugger Crocodiles and the surrounding areas to wild boar, deer, porcupines and small rodents. Central Pakistan's sandy scrublands are home to Asiatic Jackals, Striped Hyenas, wildcats and leopards. The mountainous north is home to a wide variety of animals, including the Marco Polo Sheep, the Urial, the Markhor Goat, the Ibex Goat, the Asian Black Bear and the Himalayan Brown Bear. Rare animals in the region include the Snow Leopard and the blind Indus River Dolphin. Altogether 174 mammals, 177 reptiles, 22 amphibians, 198 freshwater fish species and 5,000 invertebrate species have been documented in Pakistan.