One of the world's rarest migratory birds, barely a few steps away from extinction -- Spoon-billed Sandpiper -- has been sighted at various coastal areas in China.

Around 26 individuals were spotted at seven protected areas of southern China, a joint survey by the Mangrove Conservation Foundation (MCF) and Center for East Asian Australasian Flyway Studies (CEAAF), completed early last month, found.

Declared critically endangered by the International Union for Conservation of Nature (IUCN), less than 650 Spoon-billed Sandpipers survive in various parts of the world.

Tiny in size, these birds undertake an annual marathon migration of 7,000 kilometers to breed. En route to their breeding grounds, they make a three-month stopover at Tiaozini mudflats in east China's Jiangsu Province to moult -- a process of replacing wing feathers -- before continuing their journey to Russia.  

According to the survey, 13 birds were sighted in the Leizhou Peninsula located at the southernmost tip of the Chinese mainland. 

One Spoon-billed Sandpiper each was spotted in Yangjiang City in south China's Guangdong Province, Beihai City in southwest China's Guangxi Zhuang Autonomous Region and Zhao'an County in east China's Fujian Province. 

Six birds were seen in the Chinese coastal city of Fangchenggang, southwest China's Guangxi Zhuang Autonomous Region. 

Two birds each were observed in east China's Fujian Minjiang delta and Qinzhou City in southwest China's Guangxi Zhuang Autonomous Region. 

"The sighting covers about 3.7 percent of the bird's total population. Such a large presence of Spoon-billed Sandpiper is due to China's ban on reclamation that has revived its wintering ground," Yifei Jia, a post-doctoral researcher with the School of Nature Conservation, Beijing Forestry University, told CGTN.

Surveyors revealed large-scale reclamation along the country's coastal belt had been destroying migratory birds' wintering and breeding grounds for decades. Last year, the Chinese government banned land reclamation and ordered revival and nationalization of unutilized reclaimed land.

Within a year, tidal waves are reviving the natural habitat for a range of migratory birds, Jia added. From 1950 to 2000, nearly 53 percent of the country's temperate coastal wetlands were lost; landfilling was identified as a significant reason for the destruction.

"China's coastal wetlands are the vital habitat for the critically endangered Spoon-billed Sandpiper after the breeding season, providing important migration stopover sites and wintering grounds," said Terry Townshend, director of Eco-Action.

Professional bird watchers from 13 organizations and over 100 freelancers participated in the survey.

"Regular monitoring helps conservationists and policymakers identify the most important sites and prioritize their protection so that this charismatic bird can be saved from extinction," Townshend added.