How did Dalian Snake Island come from? How many snakes are there on it?

Starting from Dalian Port, bypassing Laotieshan at the southern tip of Liaodong Peninsula and sailing 20 nautical miles to the west, there is an island lying in the northwest-southeast direction on the sea. This island with an area of only about 1 square kilometer is Snake Island.

The highest point of Snake Island is 215m above sea level. There are bare cliffs in the west and north. There are four gullies in the southeast of the island, with lush vegetation and snakes in groups. This is a world of snakes. The discovery of Snake Island can be traced back to the early 1930s. At that time, because a lighthouse was to be built on the island, people were sent to other islands to inspect the site selection. However, people who went there were frightened and fled back to the mainland. Since then, the wonders of Snake Island have been announced to the world.

1963 the State Council established Laotieshan Nature Reserve to protect birds and snakes that feed on birds. Since 1980, Laotieshan has been designated as one of the national key nature reserves in the State Council, with an area of 17000 hectares. The killing of islands and snakes is strictly prohibited in the reserve.

There is no exact data on how many snakes there are on this small snake island. It was previously estimated that there were 500,000 snakes in Snake Island, and then there were 300,000, 6.5438+0.5 million, 50,000 and 30,000 snakes. These data vary greatly, which is doubtful. Until the end of 1984, the researchers adopted the "recapture marking method" in Snake Island, and obtained relevant data through preliminary calculation, confirming that there are about 12000 Agkistrodon halys in Snake Island at present, and they give birth to about 1000 cubs every year.

Obviously, this data is more reliable. Although the previous estimate was very large, it is a fact that the number of vipers on Snake Island is decreasing year by year. The reason is mainly caused by man-made hunting. According to records, as early as 1937, the Japanese invaders occupied Dalian, stole more than 7,000 vipers and transported them to Taiwan Province Province. In 1950s, more than 65,438+0,000 poisonous snakes died in flames because a bomb accidentally landed on Snake Island during a military aircraft training.

1963 before the establishment of nature reserve, it was very serious for local people to go to snake island to catch poisonous snakes indiscriminately. Someone caught more than 1000 poisonous snakes at one time! Obviously, such man-made hunting has seriously damaged the ecosystem on Snake Island. Now, with the establishment of nature reserves, the original ecological balance can be gradually restored and maintained.

The unique natural environment of Snake Island provides good conditions for the survival of snakes, and also provides a foundation for the unique ecological balance here. Snake Island is located in the ocean, with mild climate and moderate rainfall. There are many gullies, crevices and caves on the island for poisonous snakes to hibernate, which is very conducive to the survival and reproduction of snakes. The ecosystem on Snake Island is also very unique. Many migratory birds live near Laotieshan in order to migrate to the south in late autumn and early winter, looking for a warm environment.

As a result, Snake Island has become a place where a large number of islands live together. There are dozens of birds here, such as yellow-browed birds, leaf warblers, small flounder, white snipe pigeons, field owls, tits, swift and so on. Almost all of them can become the belly of poisonous snakes, and even the fiercest sparrows sometimes can't escape the trap of poisonous snakes. If sparrows are not careful in the process of fighting poisonous snakes, they will be bitten and poisoned by poisonous snakes and fall from the air. Of course, if the sparrow hawk suddenly attacks the poisonous snake quickly, it can peck the poisonous snake to death, but it will make the snake be eaten by the eagle.

Why are there so many snakes on Snake Island and they have survived for a long time? There is an interesting legend in the past: It is said that a long time ago, there lived two big snakes, a male and a female, as well as countless snakes and their descendants. One day, the male snake said to the female snake, I heard that snakes can become dragons when they swim across the sea. This island is too small. We must swim across the sea and become the dragon on the mainland, the king of the world and the king of all animals. Wouldn't that be soon? ! After that, I bid farewell to the mother snake and swam to the mainland with thousands of snakes. Who knows that the dragon king in the sea knows that the dragon king can't allow snakes to cross the sea and become dragons!

So, the Dragon King sent the Green Turtle to lead the nearby shrimp soldiers and crabs to annihilate the snakes, killing the restless sea-crossing snakes to pieces, and the male snake was also killed by the Green Turtle, leaving only a few small snakes to flee back to the island. Since then, the poisonous snakes on the island have never dared to venture across the sea again. In fact, although the viper can swim, it can't swim very far, so the viper in Snake Island won't swim to the mainland.

Scientists' research shows that the snakes on Snake Island come from the mainland. But it was not the mainland snakes that crossed the sea, nor was it brought to the island by fishing boats, but the result of land and sea changes during the geological period. About hundreds of millions of years ago, the sea level was much higher than today, or the mainland was too low. Although Liaodong Peninsula and Snake Island are connected together, they are both submerged in the sea. By 400 million years ago, the land, Liaodong Peninsula and Snake Island gradually emerged from the sea in this area. Later, after several crustal movements and sea level rise and fall, Snake Island experienced vicissitudes.

When the sea level is low, Liaodong Peninsula is connected with Snake Island, and snakes can swim directly to Snake Island. As the sea level rose, the snake island gradually separated from Liaodong Peninsula, so the snakes on the snake island stayed on the island. Although it has evolved several times, the snakes on Snake Island have not been extinct due to natural and man-made disasters. On the contrary, it has multiplied on the island with suitable environment for generations, forming today's snake island.