More on the European woodpecker:

"Yaffle \Yaf"fle\, n. [Probably imitative of its call or cry.]
(Zo["o]l.)
The European green woodpecker (Picus, or Genius, viridis).
It is noted for its loud laughlike note. Called also eccle,
hewhole, highhoe, laughing bird, popinjay, rain
bird, yaffil, yaffler, yaffingale, yappingale,
yackel, and woodhack."

Webster's 1913 (*Note: nickle ain't listed)