Due to his aging and suffering from illness, he was unable to stand up. A team of veterinarians from the reserve and Czech zoo carried out euthanasia for him. The species was first known to the scientific community only after a rhinoceros, which was killed near the White Nile in Sudan, was exhibited in 1903. In 1908, naturalists first described this subspecies from skull specimens in the Powell cotton Museum. At that time, it was found that although this subspecies was only distributed in the local area and might be affected by human settlement environment, grassland habitat suitability, savanna woodland and water source, its population was still quite large. < / P > < p > they are found in southern Chad, northern and Eastern Central African Republic, southwestern Sudan, northeastern Democratic Republic of the Congo and northwest Uganda. < p > < p > in the historical literature, there is no record of white rhinoceros between the southeastern border of the North rhinoceros (Nile, northern DRC and Uganda regions) and the northern border of the southern rhinoceros (Zambezi River), and the distance between the two borders is about 2000 km. < / P > < p > it is possible that climate and vegetation changes in the last glacial period separated this continuous range [2], and then two subspecies were formed at both ends, and it is likely that gene exchange did not take place in a longer time. In 1982, after studying the genetic differences of mitochondrial DNA, the research team pointed out that the two subspecies were separated about 2 million years ago. Although their sample size is too small to generalize, it does show that there are obvious morphological differences between the two subspecies. < p > < p > in terms of shape, the dorsal fossa of the skull is smaller, and the body hair of the adult is less. The height ratio of the two subspecies is also different, and the northern white rhinoceros is relatively shorter. In the early 20th century, the number of rhinoceros albus was almost extinct in the early 20th century. However, the number of rhinoceros albus has been greatly restored since then. The current number is between 17212 and 18915. The survey of African rhinoceros from 1979 to 1981 showed that the situation of northern white rhinoceros was very serious, the number was very small, and the decline rate was very high. In 1979-80, the population number of rhinoceros albus was less than 1000, and then it was found in 1981 that the population number was no more than 700. < p > < p > at that time, poachers began to hunt rhinoceros in Africa in order to obtain rhinoceros horn. Coupled with the local civil war, the number of northern white rhinoceros decreased greatly. < p > < p > in 1993, the number of northern white rhinoceros rose to about 30; however, it did not last long. With the resurgence of poaching activities, the northern white rhinoceros was announced to have been extinct in the wild in 2008, and only 8 were left in captivity in the zoo. < p > < p > since the 1970s, conservationists worried about Zhongzhong have tried to save them by artificial breeding, collecting and storing male sperm. < / P > < p > so far, only four rhinoceros have been born, and the last two are Nagin and fatu. < / P > < p > in 2014, it was found that none of them could reproduce rhinoceros successfully. Although she gave birth to fatu, she now has a leg injury, which may damage her health if she is pregnant again. At the same time, endometrial degeneration was found in the nomogram. < / P > < p > and in the years before and after that, the other remaining northern rhinoceros in the zoo also died one after another. Now, the last male North rhinoceros Sudan has died in 2018 < / P > < p > and then they create a viable embryo in the lab – something no one has ever done before, and they don’t have enough practical experience. But this is only the beginning of the puzzle. < / P > < p > in October 2015, by coincidence, several female rhinoceros albus needed to be treated for their reproductive problems, so researchers could collect their eggs as part of the treatment. The eggs collected were sent to an animal reproduction laboratory in Italy, where scientists developed and perfected a technique for creating viable embryos. < / P > < p > on the basis of this technology, the researchers successfully extracted the eggs of Nagin and fatu on August 22, 2019, and airlifted them to Italy. Three days later, the scientists fertilized the egg with the sperm of a male rhinoceros. Another week later, two of the eggs entered the developmental stage, when the embryos could be frozen and preserved for future use. On the optimistic side, it is possible for a southern rhinoceros to successfully carry and deliver embryos from the northern rhinoceros because the pregnancy cycles of the two species are the same. But because of the shape of the cervix, it’s tricky to transfer an embryo to a surrogate mother. < / P > < p > the ultimate goal is to restore the breeding population of the northern rhinoceros to their original level, which will take at least several decades. If we have enough samples of species to reproduce a century ago, it is possible to have multiple samples of genetic diversity. However, due to habitat loss, poaching and illegal trade activities, political conflicts and other threats, three of the five rhinos have been listed as critically endangered (CR) in the IUCN Red List of threatened species. < / P > < p > with the efforts of the distribution countries and related countries to implement a series of protection measures, the number of rhinoceros poaching has continued to decline in the past five years. Compared with 2018, the number of rhinoceros poaching in South Africa decreased by 175 in 2019 (more than 80% of rhinoceros are now distributed in South Africa). < / P > < p > in the first half of this year, rhino poaching in South Africa has again decreased by nearly 53% (compared with the same period in 2019) – 166 rhinos have been poached in South Africa since the beginning of this year. < / P > < p > we also cooperate with social media platforms, Internet companies and transportation industries through market monitoring, research and public publicity to help improve their identification and processing capabilities, and help local and international law enforcement. < / P > < p > – to be a responsible traveler, to protect the ecological environment of tourism destination, to choose environmentally friendly souvenirs or to promote the sustainable economy of local communities, to reduce food waste and so on; < / P > < p > is a responsible traveler- When meeting friends who plan to travel abroad, they should remind politely that it is illegal to bring wild animals and plants and their products such as fur, meat, teeth / horn, wild plants and seeds without permission. < / P > < p > 0- If you find any behavior or clue of illegal trading of wild animals, you can report to the local forest police or platform (for example, Tencent 110 applet); < A= https://ibmwl.com/epic-games-accused-google-of-monopolizing-the-latter-which-may-have-a-better-chance-than-apple/ target=_ blank>Epic Games accused Google of monopolizing the latter, which may have a better chance than apple