Cuckoo is understood as: Because of the beautiful legend predicted by Du Yu, King of Shu, and its singing, it is better to go home. It is often used by poets living abroad to express their thoughts about their old country. The sun sets in the cuckoo's song. Turning into a crow and returning with blood, these poems convey a deep thought of the old country. I think those who came to Taiwan Province Province in 1949 will definitely think of Du Fu when they miss the mainland, and express their feelings in the form of poems. Generally express the poet's sadness.
Wild geese, flying south, usually write about wandering away to express their homesickness.