From late May to early June, Luo Pingzhao, 36, often visits the picturesque Jiuzhaigou National Park in Sichuan province to watch birds with his binoculars.
That is the best season to watch both migratory and resident birds there. The region has 27 species of birds under first- and second-class state protection in China.
Records show that it is probably the only place in China to watch the endangered migratory rufous-headed robin, which has a signature song and is quick in movement.
Luo said that he once observed China's endemic Sichuan wood owl at Jiuzhaigou after spending three nights in the forests.
"I held my breath when I heard its hoot from far to near," said Luo, from Chengdu, Sichuan province. "When I turned around I was so excited to see it."
Like him, many avid bird watchers regard Jiuzhaigou, which literally means nine-village valley, in Aba Tibetan and Qiang autonomous prefecture as a must-visit destination to observe some of China's endemic bird species.
In 1992 Jiuzhaigou Valley Scenic and Historic Interest Area was added to UNESCO's Natural World Heritage List because it meets the criterion of "containing superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance".
It is known for its scenic and aesthetic majesty, with a wondrous landscape of clear lakes, waterfalls and karst formations, along with the jagged alpine mountains.
Tourism has become the pillar industry of Jiuzhaigou, greatly benefitting villagers.
"The development of the region is always based on protection," said Du Jie, deputy head of the Jiuzhaigou Scenic Area Administration.
In 2001 the administration adopted a regulation making it mandatory for tourists staying overnight to remain outside the scenic area, and homestays and restaurants that had opened in the early days were closed.
On August 8, 2017, a magnitude 7 earthquake hit the area, leaving the significant landscape of Jiuzhaigou with scars caused by landslides, falling rocks and debris flows.
The park was closed for two years until it was announced that 85 per cent of the park would be accessible to tourists again. Last year it was fully open to visitors after much of its fragile beauty had recovered.
"The unique scenery of Jiuzhaigou has been restored almost to its former glory, about the same to the human eye as before the earthquake," Du said.
Three months after the earthquake, the administration adopted a plan on restoring the landscape, habitat of wildlife and vegetation, the main principle being that the recovery should rely predominantly on nature's ability to heal itself, complemented by any human intervention deemed necessary.
The embankments of the area's Sparkling Lake collapsed after the earthquake, forming a 40-metre-long, 12-metre-wide and 15-metre-deep gap around it. There are 24 cascading waterfalls and lakes around the site.
"The waterfalls and lakes looked like a necklace, and with one 'bead' missing, the whole necklace may be broken," Du said. "Sparkling Lake could have had a chain reaction and caused the collapse of other lakes, posing great danger to people and wildlife near the lower reaches."
A year was spent on research and developing a plan to restore the ecosystem with eco-friendly materials, with approval from UNESCO.
Nuorilang Waterfall, one of the widest waterfalls in China, collapsed after the earthquake. A 19.4-metre-long crack was formed.
Tang Ya, a professor of College of Architecture and Environment at Sichuan University who has done in-depth research on the sustainable development of Jiuzhaigou since 2006, said that if the crack were left there, erosion would have increased, threatening the safety of nearby lakes and waterfalls.
The unusual landscape of Jiuzhaigou is the result of its massive tufa (porous rocks) deposits, and the administration has fixed the crack with tufa collected after the quake, successfully restoring the scenery of Nuorilang.
The number of geological hazard sites rose from 78 to 182 after the quake, and 170 of them have been resolved using ecological engineering, such as building concrete retaining walls and protective nets.
To prepare against natural disasters, a system to monitor geological hazards has been established, and shelters and other structures are said to be resistant to a magnitude 8 earthquake.
Huang Zhiling contributed to this story.