Rufous-backed buntings, a rare bird species, left their traces again at Miyun Reservoir in Beijing after more than 70 years. The number of these plain-looking birds is estimated to be less than 1,000 worldwide, and it is one of the rarest bird species in the world.

The Rufous-backed bunting, featured with maroon spots on its abdomen, was listed as an endangered species by the International Union for the Conservation of Nature (IUCN) in 2010.

It was last seen in Beijing in 1941 by local birders in the Summer Palace, not to be seen again until 2015.

The picture of this bird was taken by a university student named Xing Chao in Beijing , who is also a member of a local university birdwatching society.

Based on recent observations and recordings, a population of 10 to 15 Rufous-backed buntings are estimated to be living at Miyun Reservoir, said Guan Xiangyu, a member of Beijing Bird Watching Society.

According to investigations into the species, Guan found that the main habitats for them are shrubland and grassland, and habitat destruction may be the reason for the reducing number of this species.

Rufous-backed buntings mainly live in the south of Kazakhstan and the border regions between Russia and North Korea where there has been no recent observation data.

In China, they are principally found in Inner Mongolia and the northeast.

Guan said the rufous-backed buntings are probably overwintering in Beijing due to hard foraging on the snow covered of the northeast.

While Zhang Zhengwang, professor at Beijing Normal University, holds that the birds' presence in Beijing is temporary. But it means their habitat is expanding, and it needs further observation to determine whether they will stay, which depends on environment, availability of food and little human interference, he added.