The global population of crested ibises, a rare bird species, has increased from seven in 1981 to more than 9,000 at present, the forestry authorities of northwest China's Shaanxi Province told a press briefing on Monday.

The species' habitat area has expanded from under 5 square kilometers to about 16,000 square kilometers, and the distribution range of the rare birds has gradually expanded to its historical area, said Dang Shuangren, director of the Shaanxi provincial forestry bureau.

The crested ibis, with its iconic red crest and long black beak, was in the past widely distributed across East Asia and Russia's Siberia. It was thought to be extinct in China until seven wild birds were observed in Yangxian County, Shaanxi, in 1981, a discovery that prompted captive breeding and enhanced the protection of the species.

Currently, about 7,000 crested ibises live in Shaanxi, Dang said.

Since the 1980s, Shaanxi has exported 14 crested ibises to Japan and the Republic of Korea (ROK), and more than 1,000 crested ibises have been bred in the two countries. With the gradual release of the birds into the wild in Japan and the ROK, crested ibises will soon reappear in their historical distribution area in East Asia, Dang said.