Yangtze River Dolphins
The Yangtze River Dolphin, also widely known as Baiji Dolphin lives only in the middle and downstream reaches of the Yangtze River. The male grows up to 2.5 meters long and the female 2.3 meters and weighs between 100 & 150 kg. It maintains a body temperature of 36℃ and has lungs. They have very poor eyesight but have a very developed and sensitive sonar system.
They are so rarely seen but are called the Goddess of Yangtze River and the Giant Panda under Water. In 2002, it was estimated there were less than 50 Baiji Dolphins in the world and was one of 12 most endangered animals in the world. The situation is more serious than the giant panda. Chances of seeing a Yangtze River Dolphin is rather slim now.
According to the history record, Yangtze River Dolphins were widely spread over the Yangtze River area, from 35km away the upstream of Gezhou Dam in Yichang County to the sea entrance near Shanghai City. It even included Dongting Lake and Boyang Lake, totally up to 1700 km river area where Baiji Dolphins live. But unfortunately, they only live in the middle stream and downstream of Yangtze River in the later due to human activities’ consequences.
Yangtze River Dolphins like to live in groups, especially during the mating season in spring. Often they will appear as couples or in small pods. They live in a wide area but required a good water temperature. So after staying in one place for some time, they may move to another area when the water temperature changes.
Yangtze River Dolphins are likely to live in deep of water. They are timid and are easily frightened. Therefore they live far away from boats and cruises. Because there are very few it is very uncommon to see them. The only possibility is when the dolphin comes to the surface to breathe.
The dolphins are carnivore preying on fish for food. They have about 130 sharp teeth. They usually feed in the morning or in the evening while swimming in the shallow water along the bank side.
The Situation of Yangtze River Dolphins in Recent 30 Years
The number of dolphins is fewer and fewer while the distribution range is generally narrowing also. The population along Yangtze River is up to 300 million people and their activities are the main cause of decline of the Baiji dolphin. During the last century, 92% of Baiji dolphin specimens died due to consequences of human activity.
1. In 1990s, the Yangtze River Dolphins disappeared in Donting Lake and Boyang Lake. Their activity area moved from the 35 km away upstream from Gezhou Dam to 170 km away downstream from Gezhou Dam. There are no Yangtze River Dolphins near Nanjing.
2. According to the research from 2000 to 2004, the dolphins live mainly along the section between Dongting Lake to Tongling;
3. The last confirmed sighting of a Yangtze River dolphin was a dead body near Nanjing section;
4. On August 8, 2007, it was officially announced the fact of the functional extinction of Yangtze River dolphins in the report by the The Royal Society of Biological.
5. On August 19, 2007, a Tongling citizen came across and videoed a mystery animal which was later confirmed as a Yangtze River dolphin by the expert from Institute of Hydrobiology, Chinese Academy of Science. This did not change the judgment about the fact that the functional extinction of Yangtze River dolphins in science sector;
6. The last time a sighting of dolphins being reported was on July 6, 2011. A fisherman saw 3 dolphins in Yangtze River which were thought to be Yangtze River dolphins.
Dolphins is on the top of the food chain, thus they have no natural enemies. The extinction is due to human over development.