Ivory-billed Woodpecker (Campephilus principalis) [XC770846]
by Rachel Webster from Tensas Parish LA, United States (double-knock)
Ivory-billed Woodpecker (Campephilus principalis) [XC871615]
by Rachel Webster from Louisiana, United States (drumming, double knocking, single knocking, double tapping)
Subspecies
Forms a superspecies with Imperial Woodpecker (Campephilus imperialis). Subspecies bairdii considered possibly a separate species by some.
The following 2 subspecies are recognised:
principalis (Linnaeus, 1758) - South-eastern USA (probably extinct).
bairdii! Cassin, 1864 - Cuba (probably extinct).
Similar Species
Pileated Woodpecker (Hylatomus pileatus) which is smaller and has dark bill, white neck-stripe across the cheeks to bill, white supercilium and throat, lacks white stripes on mantle and large white wing-patch (small patch at base of primaries sometimes visible). In flight, lacks white secondaries and has more extensive, white underwings.
References
See References.