Early Edit 0.01 Ellz, river

[RiverNotch]

Beetle-black with glinty, guilty eye the carrion crow Technically, "glinty" isn't a word, and you're missing a comma, I think. Suggested alternative: "Beetle-black with guilty glinting eye, the carrion crow". The spondee at the start works well.
comes craving; raucous raider, she cleaves the dawn "Cawing" would be more vivid here, since the thought of the crow being hungry here doesn't really matter anyway. The pyrrhic in the middle sounds awkward. Another stressed syllable here would make this more consistent with the rest of the poem.
still wrapped in dreams of sleeping souls. Rasping words Note that this is a syllable short (but the number of stresses is perfect). If you want to make this more consistent--but in this case, I don't think you need to.
escape through sashes open-cracked, up in to misted sky. "Misty" works just as well, and there is something a bit off with "misted sky" -- maybe it's because when something is "misted", it's either misted by a subject, or just plainly misted up.

She flinches like the flea has pricked when sight or sound "like the flea has pricked"? What does that mean? 
disrupts her flight. A twitch, a twist in mock distress, she calls "A twitch" and "a twist in mock distress" sounds unnecessarily redundant. Perhaps change up the first line, make the sight or sound more vivid, and continue that idea to bulk up this line, removing "a twitch"?
to warn but draws the early gun. Flash! Dashed she tumble-turns, Though the alliteration at the end is nice, this is a foot longer than the rest, bogging this scene down. A plain "she falls" would work, though the image of tumbling is, for me, too irresistible to remove, and a feminine ending for this sudden morbid break in thought might add a bit more to the work's complexity: "to warn, but draws the early gun. Flash! Dashed, she tumbles,". However, the rhyme-spondee "Flash! Dashed" with the image of the gun right before works perfectly.
a single quill spin-falls... another morning has passed to man. Another foot too long, with clunky prosody (and two extra stresses: "a SINgle QUILL SPIN-FALLS... aNOther MORNing has PASSED to MAN"). Though I can see what "spin-falls" means, it's still an awkward way to word it, and, at least for me, a bit of a cliche. Something plain would work better, I think, then "another morning has passed to man", or "another morning's passed to man".

Still things of blood, skinned, feathered or spined, Weird line. One and a half feet deficient, with only five stresses, and an unnecessarily heavy middle section: "still THINGS of BLOOD, SKINNED, feaTHERED, or SPINED". The image is a bit muddy, too, especially with "skinned" shows the corpses had their skins removed, while "feathered or spined" showing that they hadn't; yes, "skinned" can also mean "has skin", but "skinned" in that sense is always used in combination with a modifier, and animals with feathers or spines also have skins. Perhaps "Still bloody corpses, bare-skinned or feathered or spined,"?
lie spread and flat on tar grit roads, but gone before the fox awakes. This is eight feet. Way, way too long compared to the rest of the poem, with the description being a bit drab. "lie spread and flat on tar grit roads" can definitely be shortened.
Wings whiffle down to empty lanes and hide in hawthorn spiked One foot too long -- "to empty lanes and hide in hawthorn spiked" can probably be shortened.
in white; then swoop to swallow shreds of red from dead of night. "dead of night" does not sound right, especially with the story being already set in a morning-context. The semicolon could be replaced with a comma. One foot too long.

Far afield, the dappled drays, full stretched on grass as damp Note that "full stretched" takes a bit of a stretch to be an iamb.
as river beds, the mares from night plume golden mists to lift This image is a bit of stretch to read. The drays are set up as the sentence's subject, yet they never connect with the predicate (and drays are carts; they don't necessarily include the horses, and they never are just horses -- plus, it's even more of a stretch to think that both horse and cart are so dappled, if you really meant both); "the mares from night plume golden mists to lift" is odd, since that either means the horses are farting/burping, playing with the mists (though with their drays being stretched out, this sounds off -- the mares won't be there unless they were the ones who drove the drays, and they wouldn't run around with their carts just being there), or being, actually, the horses of the moon/sun, pulling the dawn into the scene (but that would be a much bigger stretch). Change or clarify this. Also, one foot too long.
themselves into the sun. They steam like engines coaled and fired; Wait, the mares "plume golden mists to lift themselves into the sun"? That sounds ridiculous. And the second image again evokes, for me, the image of horses passing gas. Also, one foot too long.
shimmered and shivered in to the working day. Prosody's a bit off: "SHIMmered and SHIVered INto the WORKing DAY." [b]The semicolon of the line before should be a comma. This line kind of works, but with the earlier lines of this stanza, this also doesn't really fit. [/b]

See now how God awakes and breaks the wraiths that swirl Prosody's perfect, though I'll need a second judgement on "See now how God" -- I can't tell if that's "SEE NOW how GOD" or "see NOW how GOD".
and scurry through dove-cooed oaks. Look where the steeple Prosody's off: "and SCUrry through DOVE-COOED OAKS. LOOK where the STEEPle". On a more subjective note, the image of the very human drays does not blend well with the later image of the very natural-divine image of the dawn -- The earlier stanza should either remove the image of the drays, or be more balanced line-wise with the transition (two lines for the human, two lines for the return of the morning).
sheds the shroud, where naked branches starkly sway; Note that this is one syllable short, at the beginning. The image, though, is beautiful, and works really well.
a gentle shifting in the air. April has brought an early spring. Fair ending. This is two syllables too long -- the length doesn't fit, I think, such a light (in the sense of bright and uplifting) ending. "a gentle shifting in the air" could definitely be shortened into the just as clear "a gentle wind" -- "a gentle wind. April has brought an early spring." I have to say, though, throughout the poem, [b]I did not expect spring -- I somehow expected something bright,[b] sure, but this jump from the post-vespertine to the pre-vernal is quite the jump.[/b][/b]

In general, your mix of alliteration and accentual-syllabic verse is amazing (and, besides the flops with the meter, really, really natural), and your imagery is solid, without being overwrought. Thanks for the really, really good read!