CHENNAI: “Elephant herds are usually led by the oldest females in the herd. Soon after the male elephants in the herd attain 13 or 14 years of age, they will be driven out of the herd. There is no permanent herd for male elephants,” Osai Kalidas explained. During the mating season, the ousted young males search for females and tend to join new herds. They again leave the new herd and search for another herd. During this period, they may travel alone and tend to enter human settlements. “Home range for each herd is around 500 sq km. But male elephants require more space and face challenges while entering new territories,” he added. Also, continuous forest in the State is rare and human settlements are located close to forest areas. This encourages some lone tuskers to raid crops.