And soon that toil shall end; Soon shalt thou find a summer home, and rest, And scream among thy fellows; reeds shall bend, Soon, o'er thy sheltered nest.
Well, the speaker is still talking about the waterfowl's intense labor as we begin the sixth stanza, and he's being very alliterative ("soon," "soon," "summer," etc.) about it. (Check out "Sound Check" for more.)
He says that "soon" the waterfowl's "toil shall end," and then he'll go find some awesome summer place, rest up, and hang out with his waterfowl friends.
And then he'll have a nice, "sheltered nest," and the reeds near whatever body of water he chooses will "bend" over his nest. Aw, isn't this just a lovely little picture?
It's also just a wee-bit unnerving because, well, it kind sounds like the whole thing is a metaphor for… death.
Wait—how do cozy nests equal death, you ask?
Well, the speaker has already put death in our heads (remember the "fowler" from the second stanza?). What's more, all this stuff about an end to toil and resting just sounds kind of like an end of life. You can imagine somebody like your grandfather saying something like "after all my tears of toil and labor, I can finally… rest."
At the same time that this all sounds kind of ominous, it's also a little hopeful. The waterfowl will at long last find a sheltered place to kick up his feet (webbed or otherwise). In addition, he will be in the company of all his waterfowl friends.
The speaker then is really driving at two things here. First, he's imagining the waterfowl's return to the land as a kind of death—an end to toil and the pain of the "cold, thin atmosphere," etc.
He's also, on a different level, imagining the waterfowl's return to land as a return to his community. It's a move from the cold solitude and loneliness of the sky, to the warm, friendly environs of the nest. The wanderer, you could say, is returning home. Good times, gang.