Williamson's Sapsucker (Sphyrapicus thyroideus) [XC109904]
by Bruce Lagerquist from Upper East Fork Ute Creek, Costilla Co., Colorado, United States (call)
Williamson's Sapsucker (Sphyrapicus) [XC736448]
by from Upper Beaver Meadows-RMNP, Larimer Cty, Colorado, United States (drumming)
Subspecies
Has hybridized rarely with Red-naped Sapsucker (Sphyrapicus nuchalis).
The following 2 subspecies are recognised:
thyroideus (Cassin, 1851) - Southern British Columbia south through Cascade Range and Sierra Nevada to northern Baja California (San Pedro Mártir Mts).
nataliae (Malherbe, 1854) - South-eastern British Columbia south through Rockies to Arizona and New Mexico. Winters in south of range and south to south-central Mexico.