Archaeological research reveals the indigenous inhabitants to have been hunter-gatherers who subsisted on a diet of fruit, fish, taro and game. From c.4000BCE, repeated migrations from South-east Asia repeated them with a new Indonesian race that was mostly composed of Malays and sea-going Melanesians. It was not until the Dongson civilization spread from Vietnam and southern China around 3,000 years ago, however, that large Cultural changes took place. The appearance of the Dongson initiated the spread of rice cultivation and irrigation across the islands, as well as the introduction of the water buffalo as both a beast of burden and a source of food. The custom of sacrificing a buffalo was also adopted from the Dongsons and is still followed in Sumatra, Sulawesi and Nusa Tenggara.
By the 7th century BCE, the Indonesian archipelago was home to well-organized societies in which people tended irrigated rice paddies and raised domesticated water buffalo, chickens, pigs and dogs, and rural kitchens were stocked with foods such as bananas, breadfruit, coconuts and yams.