Dingoes probably arrived in Australia between 4,600 and 5,400 years ago, long after the first humans, spread rapidly across the continent and probably contributed to the extinction of even more native species such as the Thylacine, Tasmanian devil, and Tasmanian nativehen. The current period of invasive species introduction began in 1788 with the arrival of the first European settlers. The population density in Australia beyond the coastline and major cities has been very low since the arrival of European settlers and there are large tracts of land where, it is very difficult for people to manage even large feral animals like camels, horses, donkeys and water buffalos.