Human beings cannot live without rare birds.

Red-crowned Crane / Picture Source @ Tupe Creative

For thousands of years, human beings and birds of all kinds have lived together in the "global village" and established a close partnership with each other. Birds' excellent flying ability, bright colors, pleasant singing voice, wonderful instinctive behavior and the ability of migration and navigation not only arouse people's curiosity, but also give people the enjoyment of beauty and scientific enlightenment.

Today, more than 10000 species of birds are known in the world, while 1445 species of birds have been recorded in China. On the occasion of the 51st Earth Day, let's go into the world of red-crowned cranes, the aristocracy of birds, and explore the natural world in which human beings and birds coexist.

The World of Red-crowned Crane

Red-crowned crane

Talking about Marriage

From March to April every year, flowers bloom in spring, and red-crowned cranes move from overwintering places such as Yancheng in the south to Zhalong in Heilongjiang Province in the north to carry out a new breeding cycle.

Two interdependent little red-crowned cranes

After the red-crowned crane is three years old, it is almost the same as the adult crane in appearance and weight, so it is the age of "talking about marriage". Every spring, they travel a long way from the overwintering ground to the breeding ground, and after making some adjustments, they begin a romantic courtship among their groups. Interestingly, after successful pairing, the cranes sometimes change their long-formed personality traits from meekness to belligerence. Especially for those red-crowned cranes who already have "children", without the fanaticism of falling in love, they need to make an effort to obtain the consent of their "children" in order to carry out a new round of breeding. After a long overwintering period in the overwintering area, parents lead their "children" to drive their existing "children" out of their previously selected nest areas in order to concentrate on a new round of "childbearing" when they return to their breeding grounds in early spring. At first, the "children" were extremely reluctant to leave, and after being driven out, they would return to their parents again, often after several times of repetition, or even their parents pecked their heads so badly that they had no choice but to leave.

basic necessities of life

The red-crowned crane was called "crane" by the ancients. What do they eat in life? in fact, in real life, red-crowned cranes eat "recipes" that really contain seafood and "Dragon Palace" treasures. Such as: all kinds of crabs, sea fish, sea shrimp, conch, seashells, aquatic insects, tadpoles, sea earthworms, water snakes, water rats and so on, as well as grass seeds, plant buds, grains and sparrows and so on. In addition, it also eats some hard substances such as sand and gravel to help digestion.

The red-crowned crane is looking for food.

In addition to resting at night, red-crowned cranes spend most of their lives looking for food to replenish their energy consumption. They constantly peck the ground with their long pointed beaks, and have developed excellent foraging skills, which can go deep into the soil layer of 10 to 15 centimeters to find something to eat. When preying on fish and snakes, they often peck at the head of fish or snakes with their unique pointed beaks, leaving them dead to eat. When preying on crabs, they decompose their chelate feet one by one and then swallow them one by one. Red-crowned cranes love cleaning very much, and all animal foods are often washed in water before eating them when there is water.

The sea is the dragon world, and the clouds are the hometown of cranes.

The dragon, grows in the sea, the sea is the "dragon palace"; the crane, soars in the blue sky, the cloud is like its home. This is a metaphorical statement, indicating that the dragon was born in the magnificent sea and has great energy, while the crane taking the cloud as its home is a symbol of nobility. In fact, red-crowned cranes shelter from the wind and rain, there are six homes: open plains, swamps, lakes, grasslands, reeds and riparian marshes, migration season and winter, sometimes also inhabit farmland and arable land.

Red-crowned cranes marching in the grass

Red-crowned crane needs a clean and open wetland environment as its habitat, which is the most sensitive to the change of wetland environment. It is active during the day and rest at night. when the cranes are perched, one or two cranes "stand guard", stay alert, look around from time to time, and issue an "alarm" when they find danger. When cranes sleep, they often stand upright on one leg, twist their neck and put their head on their back, or insert their pointed beak into their feathers. The red-crowned crane has few natural enemies, its eyes are sharp, it moves quickly, and it can fly well. coupled with its strong feet and a long sharp mouth, the eagle shuns when it sees it.

High flying cranes, thousands of miles from year to year

The bones of red-crowned cranes are hard and seven times stronger than human bones. It has a strong ability to travel, especially when it is migrating, it is often arranged in an ingenious wedge, so that the individuals behind can make use of the air flow generated by the individual in front of them in turn, so as to carry out a fast, labor-saving and long-lasting flight at a speed of 90,135km per hour at an altitude of about 400m, with a maximum of no more than 1000 m. The maximum migration distance is 2600 km.

The Red-crowned Crane / Picture Source @ panoramic Vision with wedge-shaped formation

During the overwintering period, the main cluster behaviors of red-crowned cranes are migration cluster, nocturnal cluster, low temperature cluster and other clusters. After the red-crowned crane migrates to the overwintering area, a large clustering behavior occurs every time a cold wave occurs, but after the cold wave, even if the temperature still does not rise, the crane flock will gather together again. When the autumn migration ends, the overwintering population enters a stable stage, and when the ambient temperature drops below-4 ℃, large clusters occur almost every day in the process of foraging.

"Sentinel" in foraging of overwintering red-crowned cranes in Yancheng Nature Reserve

Migration is an instinct for birds to actively adapt to changing environmental conditions. Migratory birds, that is, birds that change their breeding and wintering places with the change of climatic conditions. Migratory birds are divided into winter migratory birds, summer migratory birds and migratory birds. The resident birds are resident birds all the year round. Red-crowned cranes are winter migratory birds in Jiangsu and summer migratory birds in the north.

Spring goes to autumn every year, over and over again. From late September to early October, the northern part of the breeding area of the red-crowned crane was affected by the cold wave, and when the daily average temperature dropped steadily below 3 ℃, the red-crowned crane began to migrate to the overwintering area, and the cluster was mainly in the middle and later stage of migration. each time under the influence of strong cold air in the north, it advanced southward to reach the overwintering area and overwintered in the south. In the following year, from late February to the first and middle of March, it migrated northward from the overwintering ground to the northern breeding ground for breeding.

Why do red-crowned cranes bother to make an annual migration over long distances? ornithologists have put forward many reasons, among which climate change is the most important. During the Cenozoic Quaternary ice age, when the cold wave in the Northern Hemisphere hit from north to south, the weather in the north was extremely cold and everything was covered with ice and snow, seriously affecting the survival of birds. They are forced to leave their long-li