形容词是migrated ，migrate做及物动词时有偏移，移居，移植的意思 ，所以它的过去分词形式也可以理解为形容词 放在句首

举个例子，migrated line. 偏移测线，migrated depth section 偏移深度剖面 migrate是动词，译为迁移，移居。它的形容词两个: 1. immigrant 移来的,移民的

migrate的形容词是migratory，migratory中文意思是adj. 迁移的；流浪的

Early in his research, Kramer found that caged migratory birds became very restless at about the time they would normally have begun migration in the wild.在克雷默早期的研究中，他发现被关在笼中的候鸟在它们通常开始在迁徙的大致时间会变得非常不安。