John Clare opens with a declaration, "I love to see", and then steps out of the way. The speaker never claims the scene again. What remains is a winter heath caught in the middle of being busy, and the poem's central idea is that this season, which looks bleak and dead, is full of small restless life. The speaker loves the heath as it is: withered, rotten, boggy and cold.
The cast is humble. There is bracken curling into gorse and heather, a heron lifting off a lonely lake, a crow swaying on a "half rotten ashtree's topmost twig", a woodcock, fieldfares, and a flock of "bumbarrels". Clare's names for things are part of the pleasure. Words like "brake", "ling", "brig" and "crimpled" are dialect or regional in flavour, and "bumbarrels" is a country name for a small bird. The effect is of someone who knows these creatures by the names his neighbours use, not the ones in a field guide. "Oddling crow" is a nice coinage, and judging by the context it suggests a lone, slightly odd bird at idle in the treetop.
The poem is driven by its verbs. The heron "starts" and "flaps", the crow "swing[s]", the woodcock "flies", the quagmire "quakes", the fieldfares "chatter", the bumbarrels "flit" and "hang" and "start". Almost nothing in the scene sits still. Clare also lets sound do some of the work. "Black quagmire quakes" rattles with hard k sounds, and "bouncing woodcock" has a springy bounce of its own. The thorn is "whistling", so we hear the wind through it. The quaking bog "beneath the tread" is the only hint that someone is walking here at all. The speaker is present only as a pair of feet and a pair of eyes.
The one emotional word in the poem is "melancholy", and it is given to the heron's wing, not to the speaker. That creates a tension with "I love". The heron seems sad, the lake is "lonely", the tree is rotting, and yet the whole is offered as something loved. Clare doesn't smooth this over. He suggests that a landscape can be melancholy and lovable at once.
The form is a sonnet of fourteen lines in mostly iambic pentameter, but it behaves unusually. It begins with alternating rhyme (brake/lake, ling/wing), then keeps returning to the same sound with "swing". The next lines interlock (twig/brig, bed/tread). Then "thorn" is left without a partner, and the poem ends in two quick couplets (rove/drove, plain/again). The rhyme never settles into the expected pattern, much like the birds. Line 11, "And for the awe round fields and closen rove", is also syntactically knotty, as if the sentence were flitting about too. "Closen" seems to point to enclosed fields beyond the heath, though the poem does not explain this.
The ending is the cleverest part. There is no moral and no turn toward the speaker's feelings, as many sonnets have. The last line is "And hang on little twigs and start again". It echoes the heron's slow "Starts" from line four, so the poem closes by circling back to restless movement. The birds hang, startle and resume, and the poem stops mid-flutter.
The only human in the landscape is the "gipsy" (the period's word) who "makes his bed" beside the ash trunk. He is placed among the wild things, sleeping in the same cold as the woodcock and the crow, and the poem treats him as part of the scene without comment.
The poem is significant because of what it chooses to value. Clare, a poet strongly tied to the Northamptonshire countryside, turns a form often used for grand feeling into a small, exact inventory of overlooked things: a rotten tree, a bog, a flock of tiny birds. The poem's effect depends on that attention. A wintry heath that most readers would pass without a glance turns out to be loud, twitching and alive.