Autumn wind does the poem's first job for it: it strips the trees and leaves the nests exposed. Edward Thomas starts from that plain fact and follows his own feelings about it. The speaker admits he missed most of these nests all summer, even ones at eye level, and feels "a little shame". That shame softens into something warmer. He likes seeing the nests "Still in their places, now first known", and he likes best the ones that have been quietly turned into something else. The central idea is that attention can arrive late and still be worth having, and that an abandoned home is not simply an ending. It becomes the ground for the next small life.
The opening is blunt. "Some torn, others dislodged, all dark" reads like a field note, and the nests "hang like a mark", a phrase that suggests both a stain on the branch and a target. Nothing here is prettified. The second stanza turns the camera on the observer. Once the leaves are gone there is "no need of eyes", so seeing the nests proves nothing. His real failure was in summer, when finding them took effort. Thomas gives the idea of seeing as a "game" a faintly comic edge: summer foliage played hide-and-seek, and the speaker lost. The word "till" ends its line and makes us wait for the wind, as he did. Even the confession is dry and understated: "'Tis a light pang" shrugs off the embarrassment it has just admitted.
The form suits this modesty. Each stanza is a quatrain, and only the second and fourth lines rhyme: dark with mark, shame with game, into with grew. The first and third lines hang loose, much as the nests do. The line lengths work in a similar way. Every second line is short, about eight syllables, and the others run to roughly ten. The short lines land with a small drop, like a held breath let go: "Some torn, others dislodged, all dark." The loosest rhyme, known with done, comes in the stanza where the speaker admits uncertainty about what "jays and squirrels may have done". The slight mismatch of sound seems to fit that doubt, though that is an inference about effect, not something the poem announces.
That third stanza adds a moral note without making a speech of it. "Boys knew them not" refers to the boys who might raid nests, and jays and squirrels are real nest-robbers. By the time the speaker sees them, the nests are safe from all of that. His late discovery is harmless, which may be why his shame is only "light". The pleasure in seeing "at home and by far roads" is a quiet, shared pleasure, with no collecting involved.
The last stanza is the richest. "Winter nests deep-hid" have been filled by chance: "leaves and berries fell into" them. After that the grammar speeds up into small events: "Once a dormouse dined there on hazel-nuts, / And grass and goose-grass seeds found soil and grew." A nest built for birds has become a larder, then a seedbed. The poem began with "dark" and ends on "grew", a verb of growth that is also the final word. Nothing is stated about death or rebirth, and Thomas lets the objects make the point themselves. Even the humble "goose-grass" is the kind of exact, ordinary name he prefers to a grand one.
Thomas was killed in the First World War, and readers sometimes hear that shadow in his hushed, unshowy poems. This one never mentions it, so it is safer to leave the reading in the text. The poem is significant for what it declines to do. It does not turn the nests into symbols with a flourish, and it does not make the speaker a heroic observer. He is someone who looked and missed things, then noticed them afterwards. The poem's lesson is that noticing late still counts, and that natural things keep being useful after they seem to be finished.