The Maui parrotbill, a critically endangered native bird, appears to be thriving in the Nature Conservancy's Waikamoi Preserve on the slopes of Haleakala.

“;The typical storyline with endangered forest birds is one of decline,”; said Sam Gon, the Nature Conservancy's senior scientist. “;To have an endangered bird maintain its population and perhaps even show signs of increasing is very encouraging and cause for celebration.”;

A two-week survey in September estimated that there are about 20 parrotbills per square kilometer of forest on the windward slopes of Haleakala between Waikamoi Stream and the Ko'olau Gap, according to the Conservancy. That was more than twice as many as a separate survey that was more limited in scope that took place in 2006.

The two surveys can't be directly compared because their methods differed. But scientists are heartened by the results of the latest census.

“;I didn't expect that there would be that many birds there,”; said Dusti Becker, an ornithologist who led the September survey and is project coordinator for the Maui Forest Bird Recovery Project. “;My sense is that it's a growing population, fundamentally because of forest recovery.”;

The Nature Conservancy has been actively managing the 5,200-acre Waikamoi Preserve since 1983, fencing out pigs, removing alien vegetation and boosting native plants. This has enhanced the habitat for the Maui parrotbill, which uses its powerful, curved beak to pry insects and grubs out of native shrubs, trees and dead branches.

The chunky bird, roughly 5 to 6 inches long, is olive green on top with a yellow stripe over its eyes. It used to be found on Maui and Molokai, but its habitat has shrunk to 19 square miles of the high windward slopes of Haleakala. An estimated 500 parrotbills remain.