Ancient poems reveal the history of Yangtze in danger in danger
The Mentions of the porpoises without yangtze fins in critical danger of extinction in ancient Chinese poetry revealed missing information on the habitat of the only freshwater in the world
Porpois without yangtze finesse.
Around 1745, the Chinese emperor and poet Qianlong sailed on the Yangtze river to the eastern city of Zhenjiang when he met a breathtaking view: a group of what we now call the porpoises without yangtze wings (Neophocaena asiaeorientalis asiaeorientalis) came out of the surface of the water. “The porpoises chased the moonlight on silver tides, while the dragons summoned counter-tolets in sight,” he wrote in a poem that was later published in the Imperial collection of poems, volume II.
Almost 300 years later, scientists wanted to draw the historic range of this bulbous head cetacean in critical danger combed hundreds of ancient Chinese poems To ask for mentions, in the hope of mapping its historical distribution and therefore better understanding the threats to this fragile subspecies. Found exclusively in the Yangtze river in China, it is the only freshwater porpoise in the world. About 1,250 individuals are left in the wild.
“Access to previous data allows us to detect when the declines began and correlated these changes with potential threats such as the destruction of housing, climate change, overhaul, the disease or the introduction of invasive species,” explains Yaoyao Zhang, an ecologist at the Institute of Hydrobiology, Academy of Chinese Sciences.
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An illustration printed in wood wood from the Ming dynasty of “Sancai Tuhui” (in English, Compendium of the Three Powers), compiled by Wang Qi (1573-1620), which is a book of poems of 49 volumes on birds and animals. This poem meticulously documents the porpoise without Yangtze fins through morphological details, overfacting postures and maternal care behavior.
“Sancai Tuhui”, compiled by Wang Qi (1573–1620) (CC by-SA))
Zhang and his colleagues turned to old poems because the official files have rarely mentioned these animals. Using an online database in Chinese literature, “we have sought various historical names of La Marsouin without elsewhere Yangtze through dynastic poetry, by manually checking each mention to ensure that it was referring to porpoise and not to other animals,” explains Zhang.
“Poets have strongly described the real behaviors of porpoises [using language] Like “blowing waves …”, “the waves that increase …” and “bow in the wind”, “she adds.
Research, published Monday in Current biologyrevealed 724 poems which mentioned the porpoises. Half contained information on where they were seen.
This window on the past has revealed that the range of porpoises has decreased by around 65% over 1,400 years, with an accelerated drop in the last century. Poems of the distant past have mentioned these animals living in tributaries and lakes along the Yangtze, but in more recent poems, these references have decreased considerably. The researchers concluded that the range of subspecies in these tributaries and lakes decreased by 91%.
A hunting in Yangtze without finesse in Lake Poyang.
The study “is based on many previous examples on the way in which historical texts of various types can help understand the distributions of past species and, in particular, the losses of biodiversity caused by humans”, explains Jens-Christian Svenning, macroecologist at Aarhus University in Denmark, which was not involved in the new research. For example, scientists have rebuilt the old composition of fauna in Greece using Descriptions of ancient epic poems. Although there can be challenges to this approach – and sometimes inaccuracies – there are “certainly a lot of potential” to apply this method to other species and in other regions of the world, says Svenning.
For their next step, Zhang says that she and his team plan to dig into the poems they have collected to search for information on “What the river looked like in the past, the size of the porpoise groups and how they could behave before their figures decrease.”
