Swallows are a common sight in most areas, from arid deserts to humid tropical forests, and even by lakes in urban centers. These small water birds are only about 18 centimeters in length and weigh only about 90 grams, but their graceful flight and aerodynamic efficiency make them a remarkable species.

Their slender bodies reduce drag during flight, and their high aspect ratio wings can generate a lot of lifting force with little resistance. However, this aerodynamic efficiency comes at the cost of reduced maneuverability. This disadvantage is partially compensated by the forked tail, which improves the bird's maneuverability.

Swallows can also live in caves and often find their homes in cavities such as rocks, brick walls, and bridges. They also nest in hollow trees in the wild. Each swallow builds a nest out of materials such as plant fibers, dirt and small pieces of paper.

In the winter, the food supply of swallows in temperate regions is greatly reduced, so many species migrate. But unlike most other passerine migratory birds, swallows migrate during the day and fly at low altitudes. Species that breed in Africa often migrate in response to rainfall patterns, but little is known about this.

Swallows are beneficial birds of nature, feeding on insects such as mosquitoes and flies, and can eat up to 250,000 insects in just a few months, making them an important ally in pest control.

Their annual long-distance trip from the north to the far south in autumn, where they can enjoy the warm sunshine and humid weather, is a remarkable feat of endurance.

In addition to their benefits and biological characteristics, swallows have also played important roles in culture and art. Swallows are generally regarded as a symbol of happiness, auspiciousness, and beauty, and people often use swallows as the subject of decorative items and artworks.

In Japan, swallows are also one of the popular animals. They are regarded as a symbol of hard work, joy, and happiness, and the swallow's nest is also regarded as a symbol of bringing good luck and protecting the family. Many traditional Japanese buildings and gardens feature swallow nests to show the owner's love and respect for the animal.

In Western literature, swallows are often depicted as figures of beauty and grace, such as the Lady Swallow in Shakespeare's A Midsummer Night's Dream. These charming birds have captured the imagination of people throughout history.

Swallows are vigorous and beautiful water birds that play important roles in both nature and culture. Although they are plentiful, we should protect them so that they can continue to play their important role in the natural environment.

This can be done by providing safe nesting places and ensuring their habitats are protected from environmental harm. By taking these steps, we can ensure the continued success and beauty of this remarkable species for generations to come.