Hawaiian petrel Hawaiian petrel The Hawaiian petrel or uau ("Pterodroma sandwichensis") is a large, dark grey-brown and white petrel that is endemic to Hawaii. The Hawaiian petrel was formerly found on all the main Hawaiian Islands except Niihau, but today it is mostly restricted to Haleakalā crater on Maui; smaller populations exist on Mauna Loa on the island of Hawaii, Waimea Canyon on the island of Kauai, Lānaihale on Lānai, and possibly Molokai. It is also reportedly seen on the Galapagos Islands. Their diet consists of 50–75% squid, and smaller percentages of fish and crustaceans. The birds nest in burrows or rock
Endemism in the Hawaiian Islands survive in the islands and whatever else was needed to reproduce. The narrowing of the gene pool meant that at the very beginning, the population of a colonizing species was a bit different from that of the remove, contributing population. Throughout time, the Hawaiian Islands formed linearly from northwest to the southeast. A study was conducted to determine the approximate ages of the Hawaiian Islands using K–Ar dating of the oldest found igneous rocks from each island. Kauai was determined to be about 5.1 million years old, Oahu about 3.7 million years old and the youngest island of Hawaii about