#人人能科普, Shinchi #Ishikawa Prefecture is located in the central part of the Hokuriku region of Japan, and the central part of Honshu Island is near the side of the Sea of Japan. From January 16 to 26, 2012, my family and I went sightseeing in Kanazawa and Wajima in Ishikawa Prefecture. What interested me the most were the wild birds that lived in the city there. The bird species I saw were not many, not rare, but they were not very afraid of people, which gave me the opportunity to observe up close.
The "city" is full of black crows
During my days in Kanazawa, the bird I saw the most was the crow. Every day from sunrise to sunset, whether indoors or outdoors, their monotonous, harsh calls can always be heard; when walking on the streets or visiting tourist areas, they are flying in the air, trees and buildings falling, and running on grass.
Kanazawa's crows are bold and will even fly to the feet of pedestrians in the park to beg for food. The crow here is about 50 centimeters long, the whole body is pitch black, and some parts are shiny with blue, purple and green metallic luster, and the appearance is solemn and noble. Upon closer inspection, I found that there were two of them: one was slightly larger, with a thick beak, the leading edge of the upper beak was almost at right angle to the forehead, and the forehead was particularly prominent, which was a large-billed crow; the other was a slightly smaller, lower forehead, and a smaller beak, a small-billed crow. Large-billed crows and small-billed crows are not only similar in form, but also have similar living habits. They often live near human settlements such as farmland and villages, and mostly feed on various insects on the grassland in summer and autumn, and feed on the leaves, buds, fruits and seeds of plants in winter and spring, which belong to the consumers of the ecosystem. If they have the opportunity, they also eat animal carcasses and all kinds of garbage, becoming decomposers of ecosystems and scavengers of nature.
One day, I saw a small-billed crow moving on the banks of the Asano River, so I stopped to observe. Due to the rapids of the river, some small mollusks and aquatic insects hide under the stones to avoid the impact of the current. The crow stood in the shallow water, turning over the stones with its beak in search of food attached to it.
Crows are said to be very clever birds, some can even open the garbage bags that people have tied up to find food, and some can use cars driving on the street to crush walnuts that they can't open.
Kanazawa Castle was built in the 16th century, but after several wars and fires, only a few buildings such as the castle walls remain. There is a forest in Kanazawa Castle, where many trees grow twenty or thirty meters high, and this forest has become a night's sleep for crows. Every afternoon through evening, flocks of crows returning from foraging gather here from all directions, gathering black and oppressively on the branches, and the noise is not stopping.
One day, the sun went down in the west, the sky began to darken, and someone broke into the crow's habitat, causing an immediate commotion. Thousands of crows startled and rushed into the air, and the cries of "ah, ah" were incessant. Later, several crows landed first on the roof of a sloping house, followed by hundreds of other crows, and in an instant the roof changed from the original light color to black, and the crows that fell a little later had to find another place to stay.
Some cities in the north of the continent also have large numbers of crows, and they also spend the night in the city in winter. According to expert analysis, this is related to the urban heat island effect. Due to the dense population of the city, the heat exhaust of factories, vehicles and residents' lives is more concentrated, coupled with the urban building structure and other reasons, the temperature in the urban area is higher than that of the surrounding suburbs, and the temperature-sensitive crows will choose the urban area to spend the night in the winter. The city park has tall trees and is rarely disturbed at night, making it their first choice for spending the night. At the same time, perching in groups is conducive to the protection of crows from predators and reduces the risk of individuals being preyed upon by predators.
The shooting angle is different, and the feathers will reflect different lusters.