Heraclitean Fire

On oceanic islands
under endless sky
many birds evolve without
the ability to fly.
The Inaccessible Island Rail,
the Stephens Island Wren,
the Réunion Sacred Ibis
and St Helena Swamphen:
all flightless; nearly all extinct;
but none were stranger than
the Flightless Falcon that once lived
on an island near Japan.
It was a ruthless hunter,
and would perch upon a rock
until below there waddled past
a Flightless Pigeon [...]