Hawai'i is known for its diverse and extraordinary natural environment, and the Islands' bird population is no exception.

During the annual Great Backyard Bird Count, conducted Feb. 17 through Monday, 70 species were reported, including some of the rarest birds in the world.

Reports came in from 22 locations on four islands, including Anahola on Kaua'i; Waipahu, 'Ewa Beach, Kane'ohe and Kahuku on O'ahu; Lahaina, Makawao and Hana on Maui; and Kailua in the Kona district of the Big Island.

Not surprisingly, Haleakala National Park on Maui and the Big Island's Hakalau Forest National Wildlife Refuge provided the most unusual sightings, including endangered native birds such as the honeycreepers 'akepa, 'apapane, 'amakihi and 'i'iwi; the nene, or Hawaiian goose; and the 'io, or Hawaiian hawk.

The most numerous birds spotted during the count were the common myna, the zebra dove, the spotted dove, the Java sparrow and the cattle egret. The first three also made the Top Five list of most frequently reported, along with the northern cardinal and Pacific golden plover.

Other species include barn owls, wild turkeys, ring-necked pheasants, black-crowned night herons and red-footed boobies.

In all, 8,072 birds were counted during the Hawai'i survey, more than double the number in 2005.

Although the national event is called a backyard count, spotters were welcome to visit parks, refuges and other areas.

Bird watchers can file their reports online until Wednesday. Since the observers could work on their own, sending multiple reports from different areas and days, there is no way of knowing how many people participated.

Nationally, 7.3 million birds representing nearly 600 species were reported as of yesterday.

The Great Backyard Bird Count is managed by the Cornell Lab of Ornithology and Audubon, with sponsorship from Wild Birds Unlimited. It is intended to engage "citizen scientists" in counting birds to create a midwinter snapshot of the numbers, kinds and distribution of birds, according to the event's Web site.

The Hawai'i Audubon Society was not formally involved in the effort, although individual members may have participated. The group is more involved in the Christmas Bird Count, an annual event that was first held more than 100 years ago.

Robert L. Pyle, who compiled "The Checklist of the Birds of Hawai'i — 2002," said the backyard count is not as established as the Christmas count and not as well-known in Hawai'i.