Williamson's Sapsucker

The Williamson’s sapsucker inhabits open coniferous and mixed coniferous-deciduous forests of western North America, and has been considered a sensitive indicator species because of its specific habitat requirements. Like other sapsuckers, it drills conspicuous rings of holes ("sap wells") into tree trunks, specializing on eating coniferous sap and phloem. Breeders switch to a diet of ants during the nestling period. In the Southwest it occupies mixed conifer forests, but may be more common in ponderosa pine (Pinus ponderosa) dominated forests in other areas. Across its range it breeds at middle to high elevations in montane spruce-fir (Picea-Abies), Douglas fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta) and ponderosa pine forests, as well as mixed deciduous-coniferous forest with quaking aspen (Populus tremuloides). It has a preference for snags as nest sites and in most places aspen snags are preferred over conifer snags. This species is on the 2007 (most recent) WatchList for United States Birds and the USFWS Federal list of birds of conservation concern due to its rarity.