Williamson’s sapsucker
Sphyrapicus thyroideus
L 8¼″
Habitat: This sapsucker prefers mixed conifer-hardwood forests of the Rocky Mountain region but also inhabits the subalpine spruce-fir-lodgepole zone, and ponderosa pine, Douglas-fir, and aspen forests.
Nest: The choice of tree species for nesting seems to differ between regions. Bent (1939), Packard (1945), Bailey and Niedrach (1965), Burleigh (1972), and Jackman (1975) reported Williamson’s sapsuckers nesting primarily in conifers. Other authors (Rasmussen 1941, Hubbard 1965, Tatschl 1967, Ligon 1961, Crockett and Hadow 1975) found a preference for aspens. Of 57 nests in Colorado examined by Crockett and Hadow (1975), 49 were in aspens, especially aspens infected by the Fomes fungus; where pines were used, there were no suitable aspen sites nearby. In Arizona, we found 17 nests in aspen snags, 3 in aspens with dead tops, and 1 nest in a live aspen.
Food: The diet of Williamson’s sapsuckers is made up of 87 percent animal and 13 percent vegetable material (Bent 1939). Most of the animal food taken is ants, and most of the vegetable material is cambium. Like the yellow-bellied sapsucker, the Williamson’s sapsucker feeds on sap, especially in spring, and picks out “favorite trees” which it taps regularly (Oliver 1970).