◎Tano
[Speaking of "deer", people intuitively assume that they have large horns on their heads and moose deer and sika deer that are walking like flying.] But the "xī deer" living in the Xishuangbanna area of China absolutely subverts your imagination. They are only the size of a rabbit, small and delicate, with a rat-like face, no horns, good at jumping, and are the smallest ungulates in the world. However, this "mini-circle meng sect leader" is in a very dangerous situation today, and is listed as a "critically endangered" species in the "China Biodiversity Red List and Vertebrates". 】
The shrew deer is only the size of a rabbit and resembles a rat, so it is also commonly known as a "rat deer".
"Rat deer": The smallest ungulate in the world
The shrew (xī) belongs to the order Mammal, even-hoofed order, suborder Rumin, shrew deer family. Don't look at the name contains deer, in fact, they have no special evolutionary relationship with deer, only the size of rabbits, and the face resembles a rodent, so it is also commonly known as "rat deer", the world's smallest ungulate, some people call it "mini world cute cult leader".
Javanese moose. The weasel is the smallest ungulate in the world, and some people call it the "Mini Circle Cult Leader".
The Tragulidae family contains 3 genera, 10 species, namely the water shrew deer, the spotted shrew deer and the shrew deer, all of which are tropical forest habitats, mainly distributed in Asia and Africa. They retain many of their original features and are of high value in the study of evolutionary biology. They were abundant during the Miocene, and 11.5 million years ago, at least 5 different species of shrews existed in a place in northern Pakistan.
The appearance of the members of the shrew family
China is the northern edge of the shrew deer distribution area, which is only distributed in the Xishuangbanna area of Yunnan Province. The Weevil shrew in the genus Wei's small shrew deer is currently the only shrew deer in China, also known as the "Yunnan weasel deer", which is also distributed in northern Thailand and northern Laos. In 1916, a man named "Williamson" described the "Yunnan weel deer" based on the skulls excavated in the "Phra Province" in northern Thailand, so the Yunnan weel deer was also known as the "Wei's little shrew deer", and its scientific name "Tragulus williamsoni" bore Williamson's name.
The size of the shrew deer is similar to that of a domestic rabbit, with short forelimbs, long hind limbs, short tail, suitable for jumping, and neither male nor female have horns. The Wyeth deer weighs only 1.3 to 2 kilograms, has a shoulder height of only 20 to 30 centimeters, and a body length of 42 to 63 centimeters. Its body is ochre brown on the back, slightly darker in the center of the back, the ventral surface is yellowish-white, it often has light spots on the throat and thorax, white longitudinal stripes under the throat, and the male has well-developed upper canine teeth.
Male shrews have well-developed upper canine teeth, which are a sharp weapon for them to compete for a mate.
According to the available information, the classification and naming of the Wye's weasel is controversial. Previously, the shrews living on the Indonesian island of Java and southern Yunnan in China were considered to be a subspecies of the "little shrew deer", a member of the genus Shrew, with the same scientific name as Tragulus javanicus. However, in 2004, some scholars surveyed and found that a small shrew specimen from the thai herbarium in the north of the country was larger than the size of the shrew deer in these two places, and later Chinese scholars confirmed through genetic markers that the shrew found in Yunnan and the shrew on Java Island were not the same species, so the Javan shrew deer and the Yunnan shrew were designated as two separate species of the genus Shrew, and the Latin scientific name of the Thai "little shrew deer" was set as "Tragulus kanchil", and "Tragulus javanicus" was designated as two separate species of the shrew genus. Exclusive to Javanese weasel deer.
Combat effectiveness is negative points Can breastfeed while pregnant
The Wyeth's moose is a nocturnal animal that forages mainly in the early morning and dusk, feeding mainly on young leaves, stems and berries, and grass as a by-product. They are found in northern Thailand, northern Laos and southern Yunnan, and prefer to move in tropical secondary forests, shrublands, grass slopes, and sometimes into farmland. Originally small in stature, and unlike deer, they have developed and hard horns to defend themselves, and their combat effectiveness is basically "negative points", so they are timid and alert, relying on hidden and agile actions in the forest to avoid danger - they can jump and run like rabbits, and they can swim and escape when frightened.
They are obsessed with going it alone, only in estrus do the male and female in pairs, and after mating, they run to each other. The Wessler shrew can breed all year round, with a gestation period of 4 to 6 months, one cub per litter (occasionally two cubs), and can continue to be in heat shortly after giving birth, and can even become pregnant while breastfeeding. The cubs are able to stand and move quickly after birth and reach sexual maturity in about 5 months.
Weasel cubs. The weasel can breed all year round, with a gestation period of 4 to 6 months, and can continue to be in heat shortly after giving birth, and can even become pregnant while breastfeeding.
It was first discovered in China at an altitude of 700 meters
Although the reproductive ability seems to be quite optimistic, the actual living conditions of the national first-level protected animal Wye's small shrew deer are very "urgent", in the "China Biodiversity Red List • Vertebrates", it is listed as "critically endangered", only one step away from the "wild extinction", the estimated number is only about 1,000.
The Weeds deer is listed as a "critically endangered" species on the Red List of Biodiversity in China
A literature in the journal Biodiversity of China analyzed the causes and proportions of 58 "critically endangered" mammals (including Wei's small shrew deer) in China, followed by overuse (33%), habitat loss (24%), human disturbance (23%), natural fluctuations (7%), natural disasters (6%), disease (4%), unknown causes (2%), pollution and accidental death (1% each). It can be seen that the first three factors related to human activities account for 80% of the factors that cause danger.
Due to the scarcity and lack of relevant research, the International Union for Conservation of Nature (IUCN) once considered the Wessler shrew deer to be out of the country and marked the current status of the species as "data lack" (DD) on its Red List.
However, according to Xinhua News Agency, between 2015 and 2016, scholars from Beijing Normal University conducted a survey of wildlife resources in the china-Laos cross-border area in the northeast of Mengla County, Xishuangbanna, and found that the Weed's small shrew deer appeared in the higher elevation area of the northeast of Mengla County, at an altitude of nearly 1,000 meters. The study once again proved that the Vickers shrew deer has a distribution in China, which is also the first time that the Vickers weasel deer has been found to appear in areas above 700 meters above sea level. Internationally, it was generally believed that the distribution of small shrew deer did not exceed 600 meters above sea level.
A rare photograph of a small weasel in Mengla County, Xishuangbanna, Yunnan
The results of this survey further expand the geographical limit of species distribution of the small shrew deer to the north, indicating that the distribution range of the species in Xishuangbanna and even in China is more extensive than previously understood, and there may be important habitats for the small shrew deer in the upper reaches of the Nanla River at high altitude in the middle-laos cross-border area in the northeast of Mengla County.
Good hiding is the first element of settling down
The journal "Zoological Research" reported in 2010 that Southwest Forestry University and Xishuangbanna National Nature Reserve Management Bureau and other institutions carried out a joint survey from June to December 2007 to form a paper "Habitat Utilization of Wei's Small Shrew Deer Population in Mengla Area of Southern Yunnan". Their investigation found that the Wei's small shrew deer prefer to move in the middle and lower slopes of rainforests and evergreen broad-leaved forests, with a clear selection preference for low-altitude river valley shoals, mainly in the Sancha River area of Mengman (the confluence of the Nanha River and the Ashan River) and the Big Banyan Tree Area of Longmen (Dabaobao River Basin). According to field surveys, the altitude range of these two areas is 690 to 936 meters, the river surface is wider, the water flow is slower, the slope on both sides is gentle, and the vegetation is dense. For the timid and alert Wye's moose, such an environment helps them to quickly escape or hide nearby when they encounter predators.
The choice of vertical spatial structure of vegetation by the Wessler deer is also closely related to safety requirements. They have high requirements for forest cover density, because the dense canopy of trees can provide a higher density of branches and leaves at the top, ensuring a higher "depression closure" of the understory environment (referring to the ratio of the total projection area of the canopy in direct sunlight to the total area of the woodland), which is a good hiding condition for the Vickers small shrew deer, which can reduce the risk of being detected from a high place by predators. On the other hand, they also need denser shrub areas to provide good hiding conditions in order to escape the close pursuit of predators. This creates a double concealment condition, which greatly improves safety. These environments also tend to mean that food and water are more abundant. Tree cover and shrub cover were the top reasons influencing habitat and foraging site selection of Vickers shrew deer, ranking first and second respectively.
Half an hour after wading through the water can not run easy to be arrested
After each wading, the Vickers moose need to dry their fur, and their mobility becomes particularly sluggish, which can last for half an hour, so that they are easily preyed upon by many predators, and humans can catch them alive without even traps. This poses a mortal threat to the Vickers shrew.
They are timid and alert, and a little closer to their human footprints can disturb them. They may be far away from here, which causes the range of population activity to shrink in disguise. On the other hand, they may be frightened and choose to wade through the water to escape, and when they enter the water, they are "stiff", which greatly increases the unnecessary risk of individual survival.
If the forest area is overexploited, the Vickers shrew will lack enough hiding places and will be more likely to be found by people and other predators. Unfortunately, the habitat of the Vickers shrew deer is often also an area where human and animal activities are more frequent, and livestock trampling and artificial construction have seriously damaged the hideouts of the small weasel deer. Some suitable habitats have been reclaimed for rubber or flooded by the construction of hydroelectric power stations, resulting in habitat fragmentation and food destruction. In addition, illegal hunting of small shrew deer also occurs from time to time.
Yunnan Daily reported that in 2006, Xishuangbanna Dai Autonomous Prefecture built a large reservoir called "DashaBa" in the middle and upper reaches of the Nanla River, 14 kilometers from the county seat of Mengla. When the reservoir is built to store water, the formed water surface splits part of the habitat of the Vickers shrew deer, which means that if they want to carry out large-scale activities, they will inevitably need to wade across the river.
To this end, the Xishuangbanna National Nature Reserve and the relevant departments of Mengla County have specially built a bridge with a height of 5.5 meters, a width of 6 meters and a length of 29 meters on one of the flooded Wei's small shrew deer passages, and laid mud and plants on it as a "VIP" channel for shrews to cross the river, so that they do not have to risk wading. At the same time, the reserve also has an artificial breeding experimental field infirmary, research room, mating room and shelter and rescue center, and is equipped with full-time medical personnel.
Little is known about the distribution and population of the Vickers shrew deer, and an assessment of the conservation status is urgently needed, given the generally high hunting pressures within its habitat.
Original, please contact Environment & Life Magazine.
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