They practice their floating with soft breezes,
their swaying with blustery cold fronts.
On hot afternoons updrafts school them in subtlety;
on wild nights they learn thrashing and flailing
while lightning dances, thunder cracks.
All summer they rehearse in unison
for what they cannot possibly know is coming:
the chilly day
when they are loosed, uncounted, from their branches
to lend form to the wily air
as it races through streets, eddies in alleys,
plays at the corners of buildings.
Then, briefly, they roam in the shapes of things,
they have never seen or imagined --
armies retreating in chaos, whirlpools,
startled gazelles leaping.