"bird of passage" 的定义和意义

What is the origin of the idiom "bird of passage" and when to use it?

The idiom "bird of passage" originates from the idea of migratory birds that travel from one place to another with the changing seasons. These birds, known as "birds of passage," fly long distances in search of better conditions and resources. In an idiomatic sense, it is used to describe individuals who frequently move or travel, often without settling in one place for an extended period. The term conveys the idea of transience and a wanderer's lifestyle.