The weather in Luding, Gansu
Scientific name: Raccootidae
Nicknames: flower bear, pig head, dog, big raccoon, E Qu, a fierce leopard, a fierce beast, an iron eater and a panda.
English name: giant panda
classify
Xiong Ke Carnivora (Xiong Ke)
Endangered information
Endangered Species Convention: Appendix I
IUCN: Endangered
State key protection level: level 1
China's Red Book of Endangered Animals Grade: Endangered
Appearance characteristics
Giant pandas are fat and bear-shaped, but their heads are round and tails are short, and their heads and bodies are black and white.
distribution range
It is limited to the high mountains and deep valleys that transition from the upper reaches of the Yangtze River to the Qinghai-Tibet Plateau, including Qinling, Minshan, Qionglai, Daxiangshan and Daxiangshan. Qinling Mountains are distributed in the southern foothills, with Foping as the main county, Yangxian as the general county, and Taibai, Ningshan and Zhouzhi as only a few counties. Minshan series is generally distributed in Sichuan except Wenxian County, Gansu Province. Pingwu, Qingchuan and Beichuan are the main counties in Sichuan, Jiuzhaigou, Songpan and Maoxian are widely distributed, and Anxian, Mianzhu, Pengzhou, Shifang and Dujiangyan are a few counties. Qionglai Mountains are mainly distributed in Baoxing, Wenchuan and Tianquan counties. The general counties are Dayi and Lushan, and only a few counties are Qionglai, Chongzhou, Kangding and Luding. In addition to Hongya and Mianning, there are only several counties such as Yingjing, Shimian, Hanyuan and Jiulong in Xiangling. Except Mabian, Meigu and Yuexi, there are only Ganluo, Ebian and (Pan,1988; Ma,1988; Hu, 1985).
living environment
Giant pandas live in the high mountains and valleys in the upper reaches of the Yangtze River, which is the windward side of the southeast monsoon. The climate is warm, cool and humid, and the humidity is often above 80%, so they are wet animals. Their active areas are mostly in ravines, mountainside depressions, river valley terraces and so on. , generally in the gentle slope terrain below 20. These places have fertile soil, dense forests and arrowheads growing well, which constitute an excellent food base, with relatively stable temperature, good hidden conditions and abundant food resources and water resources.
Living habits
Except in estrus, I often live a solitary life and walk day and night. The nesting area is 3.9-6.4km2, and individuals overlap. The nesting area of males is slightly larger than that of females. The females only live in the nuclear domain of 30-40 hectares most of the time, and the nuclear domains between females do not overlap (Hu et al., 1985). The food is mainly about 50 kinds of bamboo in alpine and subalpine mountains, and I occasionally eat other plants and even animal carcasses. I eat a lot every day. I drink water from springs or streams every day. Sexually mature 6.5-7.5 years old, more estrus than in April. Usually at the beginning of September of that year, they give birth in the nest of Gushudong, each nest is prolific 1, and occasionally they give birth to two nests. The cubs leave their mother after a year and a half. The ratio of male to female in the venue is about 1: 1 (Liang,1993; Wei, 1994).
Critical factor
1, forest harvesting. The annual cutting area of giant panda habitat is at least 6,543,800 hectares. Its habitat is disappearing at a rate of about 2.5 square kilometers per year (Kreman et al., 199 1). In the past 30 years, the population of giant pandas in Shaanxi, Gansu and Sichuan provinces has doubled, reaching more than 430,000 people, and the number of large forest industry enterprises has reached 27 * * * from 1950- 1985 (excluding county-owned logging yards). The verified forest harvesting area exceeds 420,000 hectares, and the average annual harvesting area exceeds 20,000 hectares, resulting in 70% habitat destruction. 15 years later, it decreased sharply to 13, 92 1.52 square kilometers, with a reduced area of 17528.48 square kilometers, accounting for 56% of the original habitat, and it has caused pandas to disappear in six cutting areas. Only a few pandas remain in 10 cutting area.
2. Catch too much. For example, in Caopo, Wenchuan County, Britain and the United States and other western countries before liberation, at that time, more than 20 live animals were collected and captured (hunters were outside), resulting in the giant panda population there, which has been more than 50 years, and the number is still very small and has not yet recovered. Another example is Baoxing County. From 1963 to now, only one county has captured more than 1 13 giant pandas. Since the mid-1950s, more than 240 pandas captured in the wild have been exhibited at home and abroad, including more than Baoxing 1 10 and more than 60 in Pingwu, which led to the destruction of the population structure in these two counties and the sharp decline in their numbers (Hu, 1993). According to the life table analysis of giant pandas, it takes about 12 years for one generation, and the population growth is very slow. If a large number of giant pandas are caught, it will take decades to recover even if they are well protected.
3. In recent years, the phenomenon of poaching and smuggling panda skin specimens still occurs from time to time;
4. The giant panda population is distributed in more than 25 isolated island habitats. These isolated habitats are 205 square kilometers (30-2384km), most of which (67%) are less than 350km2 (Kreman et al., 199 1). The isolation and differentiation of this population is an important factor that threatens its population for a long time. The decline of inbreeding in small groups will reduce the fecundity, the survival rate of larvae and the resistance to diseases. Eventually, the members of the island will disappear. According to Pan et al. (1988)' s genetic analysis of the giant panda population in Qinling Mountains, there are more than 200 giant pandas there, which can form a breeding population of about 90, and the decline rate of generation heterozygosity is 0.54%. After 12 generations, that is, 140 years, each member will have 1/8 genes in common.
Due to the expansion of human activities, the giant panda was forced to retreat to the top of the mountain, and the bamboo species were very single. Once the bamboo blooms, there is no room for manoeuvre. Only 1975 blooms and 138 dies in Minshan area. In 1980s, Dendrocalamus giganteus bloomed in Qionglai mountain area. After the disaster, giant panda corpses were found 108, and 33 died after being rescued, accounting for 1 (Hu, 1993).
6. Unauthorized mining and pollution of giant panda habitat, as well as logging and hunting by miners are also threats (Kreman et al., 199 1).
natural history
The giant panda is a lively animal with a unique black and white coat color. Its Latin name: Ailuropodamelanoleuca refers to its black and white appearance. The species of the giant panda has been debated for a century: does it belong to Xiong Ke, or is it as close to Xiong Huan as the red panda, or is it one of its own species? The recent DNA analysis shows that the giant panda belongs to Xiong Ke and represents the early branch of Xiong Ke. Adult pandas are about 120- 190 cm long and weigh 85 to 125 kg. Unique features include: large and flat molars, one of which has developed into a "fake thumb", all of which are to adapt to the life of eating bamboo. Unlike the other six kinds of bears, neither the giant panda nor the sun bear hibernates.
Food characteristics
The giant panda's diet is very special, including almost all kinds of bamboo that can be found in the mountains. Giant pandas occasionally eat meat (usually animal carcasses). The unique food characteristics of giant pandas make them known as "bamboo bears" by locals. Bamboo lacks nutrition and can only provide basic nutrition for survival. The giant panda gradually evolved the characteristics of adapting to this diet. In the wild, pandas eat for as long as 14 hours every day except sleeping or short-distance activities. A giant panda eats 12-38kg of food every day, which is close to 40% of its weight. Giant pandas like to eat the most nutritious and least cellulose parts of bamboo, that is, tender stems, buds and bamboo shoots. Giant pandas usually have at least two kinds of bamboos in their habitats. When one kind of bamboo blooms and dies (bamboo blooms and dies periodically every 30- 120 years), giant pandas can switch to other bamboos. The continuous fragmentation of habitats increases the possibility that there is only one kind of bamboo in habitats. When this kind of bamboo dies, the giant pandas in this area will face the threat of starvation.
Imprisonment and social behavior
"Reproduction difficulty" is used as a news headline to describe the reproduction of giant pandas. However, field research shows that although giant pandas live longer in captivity, the success rate of breeding in the wild is higher. In the wild, adult pandas, both male and female, are involved in breeding. A female can mate with several competing males, and a male will look for different females during estrus. The mating season is from March to May in spring, usually no more than 2-4 days. About 5 months pregnant. Occasionally there are twins in the wild, but female pandas usually only feed one cub. Twins are more common in captive populations. Before giving birth, females look for the roots of empty trees and caves to give birth. It will stay in and around this shelter for three months, taking care of its young carefully with its wide palm. Giant panda cubs are very small at birth, usually only 100-200 grams, only about 1/900 of the female bear's weight. A few days to a month after the birth of a panda cub, the mother panda will leave the cub alone in a hole or a tree hole to go out for food. Females sometimes leave for two days or more. This does not mean that it abandons its young, but it is a natural part of the process of raising its young. The young began to eat bamboo around 12 months, but before that, they were completely dependent on their mothers. The infant mortality rate in the wild is lower than that in captivity, about 40% (edited by Pan et al.).
Long-term research in Qinling Mountains shows that the reproductive rate of giant pandas is about 0.654/female/year (Pan et al., under compilation), which is similar to some natural populations of brown bears in North America (Stringham 1990).
Giant pandas are solitary animals, and the nesting area of each adult is very clear. The nesting area of male individuals is usually very large, close to 30 square kilometers, which generally overlaps with that of multiple females. When male pandas meet in the same nest, such as around female pandas in heat, there is an obvious hierarchical relationship between them, which will lead to competition for spouses. The dominant male has the priority to mate with the female, but other males still have a chance. Female individuals are sexually mature at the age of 3-4, and male individuals are about 5 years old. Young males are in a lower position in the hierarchy and have no chance to mate until they are 7-8 years old. Female individuals are from 4 to 20 years old and usually give birth every 2-3 years. Although the only family structure of giant pandas exists only between the mother and the cubs under one and a half years old, giant pandas often communicate with each other through sounds and smells, even if they are not in estrus. Giant panda cubs are weaned at about one year old and stay with their mothers until they are about one and a half years old, until their mothers are pregnant again. If the mother is not pregnant, the cub will live with her until she is two and a half years old, when her mother will drive her away. After independence, most cubs live near their mothers, while other cubs, especially females, live far from their birthplaces. The behavior of giant pandas needs further study.
Giant pandas in captivity can live for 30 years or more, but the life span of wild giant pandas is usually only about 20 years.
history
Fossils show that the ancestors of giant pandas appeared in the early Holocene 2-3 million years ago. The giant panda's habitat once covered most of eastern and southern China, from Beijing in the north to southern Myanmar and northern Vietnam in the south (Xiale, 1993). Fossils are usually found in temperate or subtropical forests at an altitude of 500-700 meters. Great changes in the habitat of giant pandas only occur in modern times. In recent hundreds of years, the population of China has surged, occupying land and many habitats have disappeared. In the past, the giant panda once lived in a low mountain valley, but now it has become a residential area. Giant pandas can only live at an altitude of 1200-3400 meters where bamboo can grow.
current distribution
How many pandas are there in the wild? This is a difficult question to answer. Living in the dense bamboo forest on the steep mountain slope, the statistics of giant pandas has become a very hard work. There were two surveys in 1970s and 1980s, and it was estimated that there were about 1 000 wild giant pandas, which may be low. There are 37 counties in the distribution area of giant pandas. According to the three levels of main production, general production and small quantity, there are about 100 pandas in each county, and there are 7 counties in * * *; Generally, there are more than 50 counties, with * *11county; There are usually less than 50 counties with low productivity, and there are 19 counties. Based on this calculation, the total number of wild pandas is about 1000, and the number of captive pandas is about 100 (1993). The net reproduction rate of giant pandas is 1.0672, and the population growth is slow (Sichuan Provincial Precious Animal Resources Investigation Team,1977; Bi Fengzhou et al., 1989). According to the investigation of the State Forestry Administration in 2006, there are totally 596 wild giant pandas1in China, and the number in captivity is 16 1 individual. The giant panda is one of the rarest mammals in the Xiong Ke family and one of the most threatened mammals. Giant pandas live in temperate forests on the eastern edge of the Qinghai-Tibet Plateau in southwest China, where bamboo is the main undergrowth plant. The habitat of giant pandas is concentrated in six independent mountain systems: Qinling Mountain in Shaanxi, Minshan Mountain in Gansu, Qionglai Mountain in Sichuan, Daxiangshan Mountain and Liangshan Mountain. According to the investigation in 1980s, the habitat area is about 13000 square kilometers (Reid and Gong 1999). According to the investigation report of the State Forestry Administration in 2005, it has been confirmed that the Qinling population of giant panda is a new subspecies of giant panda. The Qinling giant panda and the Sichuan giant panda have been separated geographically for 50 thousand years, and the head of the Qinling giant panda is round. At present, there are 273 giant pandas in Qinling Mountains. In Qinling Mountains, brown pandas were found among black and white pandas.
The baiji (Bá i Jiì tú n) is a national first-class protected animal, also known as baiji, baiji and baiji. Vertebrates, mammals, whales, toothed whales. The baiji family was originally a freshwater dolphin, which was founded in the late 1970s at the suggestion of Professor Zhou Kaiya, a scientist in China. The only species of the genus Baiji in Cetacea. Freshwater toothed whale is a specialty of China, distributed in the middle and lower reaches of the Yangtze River. Dongting Lake, Poyang Lake and Qiantang River are also available. The body is spindle-shaped, with a body length of 1.5 ~ 2.5 meters and a weight of 230 kg. The snout is beak-shaped, narrow and long, and the tip of the snout is slightly upturned; Frontal eminence; Small eyes, located under the squab; Ear hole is very small, shaped like a needle eye, located in the back and lower part of the eye; The dorsal fin is a low isosceles triangle, located in the middle of the back, slightly behind; The fin limb is wide, the end is round and blunt, and the trailing edge of the caudal fin is concave crescent; The back is gray or blue-gray, and the ventral surface is white. Dorsal fin, dorsal fin and caudal fin are all gray or blue-gray. When breathing, the head comes out first, the splash is not high, and the tail fin does not come out. Baiji dolphin is good at diving, but it is easy to be injured by the propeller of motorboat and die. Usually in pairs. Feeding on fish, you can catch benthic fish with a long beak.
Baiji dolphin mainly lives in the middle and lower reaches of the Yangtze River and its connected waters, such as Dongting Lake, Poyang Lake and Qiantang River. Usually in pairs or above 10, they like to move in deep water and fast water. Like to live in groups, especially in the spring mating season, group behavior is more obvious. Each group generally has 2-6 heads. It has a wide range of activities, but it requires high hydrological conditions. It often stays in a fixed area for a period of time, and then moves to another area after the hydrological conditions change. Feed on fish. Baiji dolphins breed every two years, each offspring 1, and the body length is about 80 cm at birth. The newborn larvae are slightly darker in color, and the adult baiji generally has a light blue-gray back and a clean white abdomen, which is particularly bright under the sunlight. The upper and lower surfaces of horizontally extending flippers and caudal fins are the same color as the back and ventral surfaces, respectively, so the color distribution is just in line with the environmental color. Looking down from the water surface, it is difficult to distinguish the bluish gray on the back from the river water; Looking up from the bottom of the water, it is difficult to find that the white belly is similar to the strong light reflected from the water surface. This makes the baiji have a natural hidden barrier when fleeing from the enemy and approaching the prey. The life span of baiji dolphin can reach more than 30 years. Generally speaking, females reach sexual maturity at the age of 6 and males at the age of 4. Adult baiji is in estrus twice a year, from March to May and from August to 10. The gestation period is10-1month, with one litter and occasionally two litters. In the wild, the male-female ratio of adult baiji is 1: 1, but the pregnancy rate of females is generally only 30%, and the natural reproduction rate is very low.
Baiji dolphin is a carnivore, with about 130 sharp teeth in its mouth, belonging to the same type. Often swim to the shallow water on the shore in the early morning and evening to hunt. Generally speaking, the whole freshwater fish with a body length of less than 6.5 cm is the main food, and a small amount of aquatic plants and insects are also eaten. When breathing, the head comes out first, then all the water comes out, 2 meters upstream of the water surface, and then enters the water. Baiji dolphin's vision is almost zero, and it has extensive scientific research value in biology, bionics and physiology by relying on echolocation to understand environmental changes. However, baiji is timid by nature and easily frightened. Generally far away from the ship, it is difficult to get close. In addition, it has a small population and a wide range of activities, so the research on baiji in the wild is very limited.
The skin of baiji is smooth and delicate, and it has a special elasticity. The principle is the same as the elastic nylon fabric used in competitive swimming suits, which can reduce the turbulence around the body when swimming fast in water. Its caudal fin is divided into two forks, the pectoral fin on both sides is flat palm-shaped and the dorsal fin is triangular. These four fins provide excellent direction and balance control for baiji swimming in the water. Coupled with smooth and elastic skin and streamlined body, baiji can swim at a speed of 60 kilometers per hour when avoiding danger. Usually, it maintains a swimming speed of 10 to 15 kilometers per hour.
The baiji dolphin has lived in the turbid water of the Yangtze River for a long time, so its vision and hearing are seriously degraded. In water, it mainly uses sonar to receive signals to identify objects. The upper respiratory tract of baiji has three pairs of unique airbags and a throat shaped like a goose's head, but because it lives in water and makes sounds by water, it doesn't have the vocal cords needed by land animals to make sounds in the air. Through a special hydrophone, you can hear dozens of different sounds, such as the "answer" and "quack" sounds made by the baiji. Baiji dolphins often make sounds in pairs. After making a sound, they will wait for the echo quietly, so as to distinguish the distance and size between themselves and the obstacle that produces the echo and consider whether to swim to the target. It will make a new pair of sounds soon after receiving the echo, and then wait for the echo quietly for a while. After receiving the second echo, it can analyze the swimming direction and speed of the target. This is how the baiji locates the echo like an artificial sonar. With this unique sonar system, it can often catch food in the mud at the bottom of the river, and it can also send out high-frequency sound waves that people can't hear, and contact companions more than ten kilometers away.
The brain surface area of baiji dolphin is larger than that of dolphins, and the brain weight accounts for about 0.5% of the whole. Among them, the average weight of a male dolphin weighing 95 kilograms is 470 grams. This weight is close to the brain weight of gorillas and chimpanzees, and some scholars even think that baiji is smarter than gibbons and chimpanzees.