This is why I listen

First I hear the "tap, tap, tap, tap" in rapid succession,
followed by the shrill, parrot-like call.
I stand perfectly still, eyes darting back and forth,
hoping to catch a glimpse of my friend at work.
Long moments of waiting are rewarded
by a flash of red vanishing around the tree trunk.
I remain still, hoping he will reappear, and
sure enough he returns to my side of the tree,
upside down and clinging straight-backed to the slender branch,
 his chisel-like beak working swiftly.
Something startles him and off he goes,
all black and white flashes on his roller coaster flight.
This is why I listen.