As part of a long-term elephant study, biologists counted individuals in a population of elephants each spring. In one year, there were 18 males and 34 females. Over the following year, each female gave birth, from which 28 offspring survived. Predators killed 9 elephants. A construction project cleared 50 acres of nearby forested land, causing 5 males and 19 females to immigrate into the study area. Competition for females increased, resulting in the emigration of 10 males to a new territory in search of mates