Cawing shadows

At night, last light -- a shade of crows
Has perched from search on branch and caws.
  "Begone! Be done!" cuts through the wind,
The lusk of dusk on globe is spinned.
  At night, past light -- a shade of crows,
Has perched from search on branch and caws.
  Undone has come the sunset stitch.
In flood of blood as thick as pitch.
  At night, no light -- a shade of crows
Has perched from search on branch and caws.
  The last of past has fled to west.
The strife of life was put to rest.
  At night, first light -- a shade of crows
Has perched from search on branch and caws.