The island of Maui is the second-largest of the Hawaiian Islands at 727.2 square miles (1,883 km2). Maui is a leading whale-watching center in the Hawaiian Islands due to Humpback whales wintering in the sheltered ʻAuʻau Channel between the islands of Maui county. The whales migrate approximately 3,500 miles (5,600 km) from Alaskan waters each autumn and spend the winter months mating and birthing in the warm waters off Maui, with most leaving by the end of April. The whales are typically sighted in pods: small groups of several adults, or groups of a mother, her calf, and a few suitors. Maui is home to a large rainforest on the northeastern flanks of Haleakalā, which serves as the drainage basin for the rest of the island. The extremely difficult terrain has prevented exploitation of much of the forest. (From Wikipedia).