Use "returning birds" to explain that at dusk, birds still have nests to rely on, but refugees are not even as good as birds. The image of "Dissolution" accurately describes the scene of light and shade blending at dusk, which is vivid and appropriate.
As night fell, the refugees were ostracized in a foreign land and had to sleep in the countryside. This tragic situation seems endless. Full of the author's sympathy for the refugees, revealing the author's deep sadness.