Māori people peaceful tribes from their productive turangawaewae, such as the Moriori in the Chatham Islands by invading forces from North Taranaki, had a catastrophic effect on these conquered tribes. At the same time, the Māori suffered high mortality rates for new Eurasian infectious diseases, such as influenza, smallpox and measles, which killed an unknown number of Māori: estimates vary between ten and fifty percent. The spread of epidemics resulted largely from the Māori lacking acquired immunity to the new diseases. A huge influx of European settlers in the 1870s increased contact among many of the indigenous people with the newcomers. Te
Mexican Americans an army to defend themselves from invading American forces after the Mexican army retreated from Alta California to defend other parts of Mexico. The Californios defeated an American force in Los Angeles on September 30, 1846. In turn, they were defeated after the Americans reinforced their forces in what is now southern California. Tens of thousands of miners and associated people arrived during the California Gold Rush, and their activities in some areas meant the end of the Californios' ranching lifestyle. Many of the English-speaking 49ers turned from mining to farming and moved, often illegally, onto land granted to Californios