Chinese river dolphin, Yangtze river dolphin, Yangtze dolphin, Whitefin dolphin
The baiji (Lipotes vexillifer) is a possibly extinct species of freshwater dolphin. It is thought to be the first dolphin species driven to extinction due to the impact of humans. This dolphin is listed as “critically endangered: possibly extinct” by the IUCN, and has not been seen in almost 20 years. Nicknamed the "Goddess of the Yangtze" the baiji was regarded as the goddess of protection by local fishermen and boatmen.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
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PiscivoresA piscivore is a carnivorous animal that eats primarily fish. Piscivorous is equivalent to the Greek-derived word ichthyophagous. Fish were the die...
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AquaticAn aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract ...
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NatatorialNatatorial animals are those adapted for swimming. Some fish use their pectoral fins as the primary means of locomotion, sometimes termed labriform...
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ViviparousAmong animals, viviparity is the development of the embryo inside the body of the parent. The term 'viviparity' and its adjective form 'viviparous'...
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SocialNo
Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
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starts withThe Baiji is pale blue to gray on the dorsal (back) side and white on the ventral (belly) side. It has a long and slightly-upturned beak with 31-36 conical teeth on either jaw. Its dorsal fin is low and triangular in shape and resembles a light-colored flag when the dolphin swims just below the surface of the murky Yangtze River, hence the name "white-flag" dolphin.
Baiji are native to the Yangtze River of China. Historically they occurred in the middle and lower reaches of the Yangtze from Yichang in the west to the mouth of the river, near to Shanghai, as well as in Poyang and Dongting lakes, and the smaller Qiantang River to the south.
Baiji are diurnal and social animals. They occur in pairs or small groups of about 10 individuals spending the day in search of fish. They are usually quiet and shy and difficult to approach. When escaping from danger, these dolphins can reach 60 km/h (37 mph), but usually stay within 30 to 40 km/h (19 to 25 mph). Because of the poor vision, baiji rely primarily on sonar for navigation. The sonar system also plays an important role in socializing, predator avoidance, group coordination, and expressing emotions.
Baiji are carnivores (piscivores) and feed on a wide variety of freshwater fish.
The mating system of baiji is unknown. Females breed once every two years and the peak calving season usually occurs from February to April. The gestation period lasts 10-11 months after which females give birth to a single calf. The young measure around 80-90 centimeters (31-35 in) at birth, and are nursed for 8-20 months. Males reach reproductive maturity at the age of 4 years, while females are ready to breed when they are 6 years old.
The baiji population declined drastically in decades as China industrialized and made heavy use of the river for fishing, transportation, and hydroelectricity. It has been credibly claimed, after surveys in the Yangtze River during the 1980s, that baiji could be the first dolphin species in history that humans have driven to extinction. The main threats to the species included a period of hunting by humans during the Great Leap Forward, entanglement in fishing gear, the illegal practice of electric fishing, collisions with boats and ships, habitat loss, and pollution. Further studies have noted that a lack of information on the baiji's historical distribution or ecology, the environmental impact of the construction of the Three Gorges Dam on the living space of the baiji, and the failure to act for the protection of the baiji are also threats to the species. In August 2007, a Chinese man reportedly videotaped a large white animal swimming in the Yangtze. Although the animal was tentatively identified as a baiji, the presence of only one or a few animals, particularly of advanced age, is not enough to save a functionally extinct species from true extinction. The World Wildlife Fund is calling for the preservation of any possible baiji habitat, in case the species is located and can be revived.
The IUCN Red List and other sources don’t provide the total number of the baiji population size. Currently, this species is classified as Critically Endangered (CR) on the IUCN Red List, and its numbers today are decreasing.
Social animals are those animals that interact highly with other animals, usually of their own species (conspecifics), to the point of having a rec...