A bird with a broken wing lies in falling water, struggling on the grass beside a lake. The scene should be lovely, with blue water under a blue sky and a green bed beneath the bird, but the bird can't enjoy any of it. It flops one way, then into the rain, hunting for where the rain comes from, as if finding the source might explain or end its trouble. The repetition of "flops" and "seeking the source" makes the effort feel stubborn and pointless.
The other birds don't help. They offer only "occasional / honest chirps," which are sincere but not much use. The final lines, in parentheses, step back and say that only the injured bird knows what its suffering is like. That quiet aside seems to be the point: pain is private, and others can only watch from outside it. The mood is gentle but lonely, a calm, pretty setting set against helplessness and isolation.