Crow
"hard character" among birds
If you ask what black birds are in the city, then quite a lot of readers will blurt out: Crow! Indeed, at least four of the dozen species of Crullaceae distributed in Beijing are common black crows. They are black all over, clustered and have unique social nature. Crows are also opportunists. They are good at teamwork and cooperation when looking for food and defending against natural enemies. They even dare to harass and tease many large raptors and s. They are covered in black and look more "ruthless" temperament. The following is a four common black type of croaker birds in Beijing.
adapts to the city's big-mouth crow and small-mouth crow
big-mouth crow (Corvus macrohynchos) is one of the common crows in Beijing . They are 57 cm long and are thick medium-sized crows. Their heads and beaks are very thick from the side, and they are also called thick-mouth crows. Moreover, the forehead and the base of the beak are in a right angle. Dead animals, dead fish and prey discarded by raptors are all easy foods for them. It is this thick and thick mouth that makes them an expert in pecking animal corpses. Even in the cold winter, the frozen corpses will slowly break under the tearing of their thick beaks and be taken out and eaten by them little by little. The big-mouthed crows will also rely on clusters to drive away large raptors such as big turtles and sea eagles, and seize their food to enjoy themselves. The screams of the big-mouthed crow are thick wa and wa monosyllable sounds.
Wild big-mouth crows
Small-mouth crows (Corvus corone) body shape is similar to that of big-mouth crows , with a body length of 55 cm. , but its head is smaller than that of big-mouth crows, and its beak shape is sharper and thinner, which also gives them the nickname of thin-mouth crows. The crows with small mouths have more trembling sounds when they sing, and the crows with larger mouths have slightly longer lengths. Although the small-mouthed crow is not as big-mouthed crow, its ferociousness is even greater than that of the big-mouthed crow. In addition to searching for animal corpses, they also actively attack all animals that have the opportunity to capture. The author once witnessed a four-mouthed crow attacking a young bird of night heron in zoo . In just a few minutes, a night heron that was bigger than a crow was eaten by them.
Small-mouthed crows are searching for food discarded by tourists on the frozen rivers
These two types of crows are more common in parks in downtown Beijing. The zoo is also their favorite shelter , because there is sufficient food supply there, and the food discarded by people is their target. Another important food source there is the meat feed that carnivorous animals raised in the zoo cannot eat, where it has a real wild feeling for them.
bald nose crow and red-mouthed mountain crow
Inside the city, the big-mouthed crow and the small-mouthed crow are highly adapted to urban life, while the bald nose crow, especially the red-mouthed mountain crow, prefer the suburb farmland and mountain environment with few people. The distribution activities of these two types of farmland and mountainous areas in the suburbs of the city are more obvious. The red-mouthed mountain crow is completely a mountain species and is rarely close to the noisy urban area.
Bald nose crow (Corvus frugilegus) looks like a small-mouth crow, but its body shape is more prominent and slightly longer than a small-mouth crow , with a body length of 47 cm. When standing, the wing length is the same as the tail length, giving people a visual feeling of a short tail. The adult bald-nosed crow has no nose feathers around the upper beak and nostrils, and the base of the upper beak is grayish-white, which looks grayish-white from a distance. The small-mouthed crow's sub-adult bird also has nose feathers, but the shape of the beak is more conical and slender.
bald nose crows like to open-field activities and often stop on buildings
Unlike big-mouthed and small-mouthed crows, bald nose crows prefer farmland and shallow mountain environments around the city. They are rare in the noisy city centers. They can often be seen in farmlands, reservoirs and other environments outside Beijing in winter. They will dig out insects dormant at the roots of plants to feed, and will also cluster with big-mouthed crows, small-mouthed crows and Dawuli jackdaws.
Red-mouthed mountain crow (Pyrrhocorax pyrrhocorax) is the smallest pure black crow among the pure black crows that can be seen in Beijing. They are 37 cm long. The red-billed crows are black in color, and the most prominent feature is their red and slender beaks and red feet. Their long beaks are suitable for searching for insects such as mole crickets, grasshoppers, and golden beaks in grasslands and cultivated fields. They are distributed in the mountainous environment of the northeast to the southwest region of my country. is distributed in the surrounding mountainous areas in Beijing and rarely enters cities, so they are rarely seen in urban areas.
Red-billed mountain crows are active in grasslands among the mountains. The insects in the grass are their favorite foods. They mostly live in pairs. During the breeding period, their nests are in caves or cracks on the cliffs. In the mountainous areas, they can often see red-billed mountain crows in pairs or gather in small groups. They use the airflow to fly and play in the valleys. The beak of the red-billed mountain crow is yellowish during the young bird period, which looks like its close relatives, , yellow-billed mountain crow , but the beak of the yellow-billed mountain crow is obviously shorter and thicker than that of the red-billed mountain crow, so it is not difficult to distinguish them with a little attention.
Group activities Team wins
These Crows have also evolved a team-based that cooperates tacitly. Even different species will have cluster activities. They will forage together, discover natural enemies together, and harass and drive away medium and large raptors together. Even the raptors that many birdwatchers see when watching birds in the wild are what they help to "discover".
There are at least a dozen species of prey that can be seen in Beijing in winter. In the wild environment, these crows will stare at the prey at all times to inform each other of their safety. What’s more interesting is that can emit different alarm sounds to different birds of prey through observation.
When small raptors such as kestrel and sparrowhawk were found in , the alarm frequency of the individuals responsible for keeping watch was relatively slow. Because many small raptors are not as large as their size, they have no chance to cause any damage to them in terms of strength and speed. The individual who was on guard seemed to tell his companions: There is a small bird of prey, everyone should pay attention! At this time, some individuals with good things will even catch up with them and harassment, chasing and driving them away, looking very enjoyable.
and found that the fast-flying peregrine falcon , hunting falcon , and goshawk , which takes into account both speed and flexibility, the warning sounds were faster and louder, and it seemed to tell the companion: Here is a more ruthless character, everyone should pay attention and be careful of being attacked! Usually when encountering this situation, other similar people who hear the warning sound will make the same sound together, and the warning sound will become louder and louder and more. This phenomenon is both an echo of companions and a shock to natural enemies, but they are still extremely afraid of these birds of prey that are famous for their speed and strength.
Sea eagle eats fish, I come to watch
When I find large raptors such as grassland eagle , white tail eagle , etc., they even choose to watch . There are two main reasons. One is that the large raptors are large in size, with a relatively slow speed and lack flexibility when flying, and cannot make sharp turns with small radius. These crows are obviously smaller than those of large raptors and are more flexible and maneuverable. The large raptors will also be powerless to harass the crows and can only choose to stay away. In addition, the reason why crows like to watch and harass large raptors is that they may get food from them. When there are large raptors, it may be the time for them to catch their prey. Whether they are driving away the raptors or waiting for them to leave after they have a full meal, they will never give up this opportunity easily.
Accommodating to each other inside and outside the city
In the urban area of Beijing, crows are one of the common birds, and citizens are relatively familiar with them. In fact, as early as the Qing Dynasty, the reasons for the customs and beliefs of Manchus did not regard crows as a symbol of ominousness and obscenity, but took great care of them. When outside the pass, the Soren pole was set up in the courtyard to worship the sky. The tin bucket on the top of the Soren pole was used to hold pigs and crushed rice to support crows.After entering the Central Plains, this custom was brought to Beijing. Today, Sauron pole can still be seen outside Kunning Palace of the Palace Museum in Beijing. It has stopped feeding crows long ago, but this does not affect their living in the Forbidden City and Beijing city.
Modern urban Beijing is accompanied by urban construction and human activities, and it still provides convenient conditions for many corvus animals. The heat island effect in cities in winter makes the urban temperature higher than outside the city. Some places in the urban area such as near Beijing Normal University have become the night habitat for crows. In addition, food fed to stray cats in cities such as parks and food discarded by tourists also provide crows with a stable supply of food. These are the main reasons why they enter the city and live in the city for a long time.
The big-mouthed crows and small-mouthed crows living in cities have been adapting to the life of being with people since ancient times, and have long been familiar with human activities and the existence of people. Outside the city, bald-nosed crows and red-mouthed mountain crows have also adapted to living with people. Humans are farming, production, animal husbandry, and life also provide them with convenience for survival. Many wild animals are not inconsistent with human activities. On the contrary, many wild animals can also convert the impact of human activities on nature and the environment into living conditions that are beneficial to them.
Author: Zhang Tongtong
Editing and proofreading: Wei Yao
