More Yangtze finless porpoises,  an endangered species under top-level state protection in China, have been spotted in eastern and central China as they enter their breeding season. 

In the Yugan section of Poyang Lake, in east China's Jiangxi Province, rising temperatures have led to the appreance of more paired finless porpoises in the water.
"We often see them appear in pairs, and there are two common scenarios. One is a mother and her calf,  and the mother has a lighter, bluish-gray hue while the calf looks darker, almost black. The two always stay close to each other. In the other case, two porpoises, similar in size, are possibly a mating pair or a couple, as their annual breeding season is from March to May," said Dai Nianhua, a research fellow at the Institute of Biological Resources of Jiangxi Academy of Sciences. 
To avoid disturbing the rare creatures, researchers use drones to observe them from a safe distance, and activities like fishing and speedboat operations may disrupt the porpoises, according to Dai. 
"It's harmless to observe Yangtze finless porpoises from a distance. However, some people use speedboats in the area, which can startle the porpoises and cause them to leap higher, which is harmful for them. The biggest threat now, which volunteers are closely monitoring, is fishing, especially with lures, as it poses a risk of injuring the porpoises," said Dai. 
Beyond Jingxi, water bodies in Jiangsu Province in eastern China and Hunan Province in central China have also seen an increase in Yangtze finless porpoises coming to breed.
As a national first-class protected wild animal, population status of the Yangtze finless porpoise serves as a "barometer" of the ecological environment of the Yangtze River. 
In recent years, thanks to systematic ecological restoration efforts such as fishing bans and the creation of eco-demonstration areas, the population of Yangtze finless porpoises has increased.