Baiji

The Baiji is a river dolphin with a distinctive pale blue to grey back and a white underside. To identify one, look for its long, slightly upturned beak and a low, triangular dorsal fin that resembles a light-colored flag when breaking the water. Because it lives in the murky Yangtze River, this mammal has small eyes and poor vision, relying instead on a sophisticated sonar system for navigation and socializing. Mature females reach about 2.5 metres in length, while males are slightly smaller at 2.3 metres.

Historically, these dolphins occupied 1,700 kilometres of the Yangtze river system, including the middle and lower reaches and large tributary lakes like Poyang and Dongting. They are known to be fast swimmers, reaching 60 km/h when escaping danger. Breeding typically occurs in the first half of the year, peaking between February and April. Mothers usually deliver a single calf every two years after a gestation period of 10 to 11 months, nursing their young for up to 20 months.

Human activity has caused a precipitous population decline. Major threats include entanglement in fishing gear, illegal electric fishing, and collisions with boat propellers. Industrialization has also degraded the habitat through pollution, the construction of the Three Gorges Dam, and a drastic reduction in prey stocks. Although a 2006 expedition failed to find any individuals, leading to a declaration that the species is functionally extinct, unconfirmed sightings of large white animals continue to be reported by locals. Scientists remain concerned that the current environment may no longer support a surviving population.