The genus Halcyon refers to a group of medium-sized to small birds that are known for their stunning plumage and beautiful songs. Some of the synonyms for the genus Halcyon are Alcyon, Kingfisher, and Tree-Kingfisher. The birds belonging to this genus are found in various parts of the world, including Africa, Asia, and Europe. They are usually found near water bodies and are incredibly skilled at catching fish, crustaceans, and other small aquatic animals. These birds are also known for their unique breeding behaviors, which involve excavating nests in the soil or in the banks of rivers and lakes. Overall, the genus Halcyon represents a diverse and fascinating group of birds that are admired by birdwatchers and scientists alike.