It has been over a month since Tian Zhiwei allegedly saw the large, fluffy raptor flying, while it was hunting and living in the woods by the sea.

As a bird-watcher, Tian didn't tell anyone but a few close friends about the rare appearance of the bird until it left.

"I don't want the bird to be disrupted and frightened," Tian says.

In February, Tian, a passionate bird photographer and also an animal protection volunteer in Laoting, Hebei province, who has traveled to many places to watch rare birds, was shocked to see the large bird flying near the sea.

Initially Tian found it hard to believe but soon he recognized the bird as a female snowy owl, the same kind as the one seen in the Harry Potter movies - the letter carrier at Hogwarts. This species is among the largest raptors around.

The average size of an adult snowy owl is 1 meter tall with a 1.5-meter wingspan.

"The species only lives in the far northernmost Heilongjiang province and the Inner Mongolia autonomous region in China. It shouldn't be seen here," Tian says.

The coldest February days in Laoting only go as low as - 4 C, but in Heilongjiang it can reach - 40 C. The last recorded sighting of a snowy owl in Hebei was in 1910.

Beijing bird-watcher Li Hai-tao is one of Tian's friends who spotted the female snowy owl.

Having come to Laoting three times, driving more than 2,000 kilometers, Li finally saw the mysterious bird the third time.

"It is perhaps a once-in-a-lifetime chance, seeing the snowy owl in this place," Li says. There has not been a single sighting of a snowy owl in warmer places in China.

The ghostlike birds live a mysterious life in the Arctic, thus few scientists have spotted or tracked them before. But this winter was different. The alleged Laoting sighting is a case in point.

Canada is the major habitat in North America for the snowy owl, but it is frequently spotted migrating in the United States, including in the southern state of Florida, which has a warmer climate.

According to a report from National Public Radio in March, snowy owls started to appear all over the US around Thanksgiving in Nebraska, Kentucky, even as far south as beaches in Florida and Bermuda. In Europe, snowy owls sightings have been reported in France and the Netherlands since winter.

Snowy owls are typically found in the northern circumpolar region, where the species adopts its summer home. But its relocation to the more southerly latitudes could be attributed to it being a particularly nomadic bird, and that the population of its prey is running low in the northern region.

"The global appearances of snowy owls are definitely related," says Liu Yang, an ornithologist with Sun Yat-Sen University in Guangzhou, Guangdong province, and now a guest research fellow at Harvard University.

"Research shows that the snowy owls in different regions are not different in terms of genetics. In other words, they belong to the same population and behave similarly under the influence of environmental changes," says Liu.

Snowy owls live on rodents and other birds. In the Arctic, lemmings are their major prey.

"Last year was a breeding peak of lemmings in the Arctic, so the population of snowy owls rose rapidly," says Liu.

"Besides, last winter was very cold in the US, that may explain why snowy owls migrated so far south," Liu says. "But it is still very rare to see snowy owls in Florida and Bermuda."

wangru@chinadaily.com.cn

(China Daily USA 04/02/2014 page10)