Koalas may live from 13 to 18 years in the wild. While female koalas usually live this long, males may die sooner because of their more hazardous life. Koalas usually survive falls from trees and immediately climb back up, but injuries and deaths from falls do occur, particularly in inexperienced young and fighting males. At around six years of age, the koala's chewing teeth begin to wear down and their chewing efficiency decreases. Eventually, the cusps will disappear completely and the animal will die of starvation.