Before and after the Song Dynasty, crows were called "God Crow" and "filial piety" by the Han people, and no one said it was unlucky. This is proved by a large number of poems. From the Yuan Dynasty, it became unlucky and became a symbol of desolation, poverty and dying. This may have something to do with the Yuan Dynasty, but I haven't found enough evidence yet. Crows are kept in the Forbidden City because Manchu worships crows.
Both the Forbidden City in Beijing and the Forbidden City in Shenyang have Soren poles, which are used to feed crows. So, there must be a lot at that time, and you can't just kill them. They have multiplied rapidly, and of course there are many, and they have multiplied until now. By the way, besides crows, there are many magpies in Beijing, which should also be related to the historical background.
Extended data:
Crow (a general term for several birds of passeriformes): crow (scientific name: blackbird? Species): it is the common name of several blackbirds in the family Corvidae. Also known as the old man, his mouth likes singing.
It is the largest bird in passeriformes, with a body length of about 50 cm. The whole body or most of the feathers are black, hence the name. Feathers are mostly black or black and white, with long beaks, some with bright white collars, and Kuroha has a purple-blue metallic luster; Wings are much longer than tails; The mouth, legs and feet are pure black. The distance from the nostril to the forehead is about 1/3 of the length of the mouth. The nose must be straight and reach the middle of the mouth.
It mainly inhabits various forest types, such as low mountains, broad-leaved forests in plains and mountains, mixed coniferous and broad-leaved forests, coniferous forests, secondary mixed forests and artificial forests. , especially in sparse forests and forest margins. Mostly resident birds.
Strong clustering, a group can reach tens of thousands. Live in groups in forests or fields, especially in forests and grasslands, and most of them nest in trees. Mainly foraging on the ground, the gait is stable. Except for a few species, they often nest in groups and wander in groups in autumn and winter.
Complex behavior, showing strong intelligence and social activity ability. The singing is simple and rude. Generally fierce and aggressive, they often prey on eggs and chicks in waterfowl and wading nests. Omnivorous, eating grains, berries, insects, carrion and eggs of other birds. Many species like to eat carrion. It is distributed almost all over the world.
Living habits: Crows like to live in groups, which are strong in clustering, and a group can reach tens of thousands. Living in groups in forests or fields, they are forest and grassland birds, mainly foraging on the ground, and their gait is stable. Except for a few species, they often nest in groups and wander in groups in autumn and winter. Complex behavior, showing strong intelligence and social activity ability.
The singing is simple and rude. Generally fierce and aggressive, they often prey on eggs and chicks in waterfowl and wading nests. Some crows in captivity can "talk", and some crows raised in the laboratory can learn to count to 3 or 4, and can find marked food in the box.
Baidu Encyclopedia: Crow