Williamson's Sapsucker

The Williamson's sapsucker, Sphyrapicus thyroideus, is a medium-sized woodpecker with a striking sexual dimorphism. Males boast an iridescent black plumage on their head, back, sides, and tail, accented with a white stripe behind the eye and another across the head. Their chin is a vivid red, and their belly a bright yellow, while their wings feature prominent white patches. Females, on the other hand, present a stark contrast, being mainly black with a pale yellow breast, a brownish head with black streaking, and fine barring on the back, breast, and sides.

Identification Tips

The Williamson's sapsucker is 8.3-9.8 inches (21-25 cm) and weighs 1.6-1.9 ounces (44-55 g). Males are an iridescent black with a red chin and yellow belly whereas females are black with a pale yellow breast and brownish head.

Habitat

Williamson's sapsuckers favour open forested areas with a coniferous composition, particularly ponderosa pine, Douglas-fir, and grand fir. Subalpine fir and western larch are also significant to their preferred habitat.

Distribution

These birds are partially migratory, breeding in western North America from northern Mexico to British Columbia. Some populations are permanent residents, while others migrate to central Mexico, forming small flocks during their journey.

Behaviour

Williamson's sapsuckers are known to excavate a new nesting cavity each year, occasionally reusing the same tree. They drum to establish territories and are associated with mature larch forests, particularly in south-central British Columbia.

Diet and Feeding

Their diet consists of sap, primarily from conifers. During the nesting season, insects become their main food source, and they also consume berries outside of the breeding period.

Conservation status

The IUCN lists Williamson's sapsucker as Least Concern, but the species may be declining in some parts of its range due to habitat loss. In Canada, where less than 500 individuals breed, the species was designated endangered in 2005 due to rapid habitat loss from forest harvesting.