Despite the name of the bird being blue, only the males stand out for the bluish color in their plumage. Females and young are commonly brownish-brown.The bluebird can have its shades of blue varied, being completely dark when adult. However, they may have brilliant, sparkling blue eyebrows and coverts, with a black beak.This bird measures about 16 cm in length and has a life expectancy of 20 years. Wild birds are often larger. They are territorial birds, so they are rarely found in flocks. In this way, when they are born, the puppies usually live with their parents, however, when they enter the adult stage, they usually live independently.Because they are territorial birds, when a male invades the territory of another, it is common to have fights. However, there is a certain respect among the birds, even so, it is not impossible that some male try to invade to conquer a female or the territory.