Whenever a strong earthquake hits Southwest China's Sichuan province, panda lovers across the world feel their stomachs tighten with worry.

A magnitude 7.0 earthquake rippled through Jiuzhaigou county, a popular scenic area for tourists, at 9:19 pm on Tuesday, after originating 20 kilometers below the earth's surface.

The China Conservation and Research Center for the Giant Panda quickly confirmed that the base's staff and animals, 400 km from the epicenter, were not affected.

Preliminary checks confirmed that no pandas were hurt and their breeding houses in the center's several reserves remained intact.

However, the earthquake was near a panda migration corridor and might have some effect on the wild population in the area, according to Gu Xiaodong, deputy director of a local wildlife protection station.

Giant pandas live mainly in the mountains of Sichuan and neighboring Shaanxi and Gansu provinces. Because of habitat loss and low birthrates, only about 1,800 pandas still live in the wild, while some 300 live in captivity.

Panda reserves cover about 60 percent of their natural habitat and are home to 70 percent of wild population.

They live mostly in Sichuan, where earthquakes and fragmentation of habitat have affected breeding patterns.

Secondary disasters, such as rock slides and barrier lakes, also change the habitat, cut off food sources and increase risks to the wild population.

On May 12, 2008, a magnitude 8.0 quake damaged Sichuan's Wolong Panda Reserve. Most of its pandas and staff were transferred to another facility in Ya'an, 140 kilometers from Chengdu, the provincial capital.

That facility fell victim to similar circumstances when a magnitude 7.0 earthquake hit Lushan county on April 20, 2013. The center reported minimal damage, and all its 61 pandas were uninjured.

A new panda breeding and research center, sponsored by the government of the Hong Kong Special Administrative Region, has been built on less rugged terrain in the Wolong reserve. It can accommodate 80 captive pandas.

Two years after the quake, Wolong restarted its program of training captive-bred pandas to live in the wild.

Gu said that after the 2008 quake a giant panda rescue plan was introduced. Local residents are required to report sightings of any injured panda to a wild animal protection center, which will send veterinarians and center staff to check its condition.

Local forestry authorities also take measures to restore panda habitat after earthquakes. In 2016, the provincial government presented a plan for a giant panda national park that would unite isolated habitats.

The park, which will cover 27,134 square kilometers, aims to restore migration corridors linking 67 panda reserves in six isolated mountain ranges. The corridors will allow wild pandas to mate with pandas from other areas to enrich their gene pool and raise their numbers in the wild.

Xinhua