Williamson’s Sapsucker

Sphyrapicus thyroideus
Range Map

The Williamson’s Sapsucker breeds in open forested areas with conifers, mainly ponderosa pine and fir. The males and females look so much different; They were believed to be different species when first discovered by John Cassin in 1852. A generation later, in 1873, Henry Wetherby Henshaw was the first to recognize that the two ‘species’ were one when he observed both birds attending the same nest hole.

The rapid disappearance of mature forests in British Columbia has taken a toll on these birds. They were declared “endangered” there in 2005.

Historically, science recognised two subspecies of Williamson’s Sapsucker. The two members were S. t. nataliae and S. t. thyroideus. Each of these were named in the mid-1850s by prominent ornithologists of the day. In the late 1990s, researchers began discovering clues that started them questioning the validity of subspecies for these birds. In 2002 and 2003, Micheal Patton and Phillip Unitt completed a study that helped establish the view that the Williamson’s Sapsucker is monotypic (i.e. no subspecies).

I’ve enjoyed several encounters with these birds. I met a juvenile on Santa Rosa Mountain in 2010, a male and female near Mono Lake (California) in 2014, another adult pair near Jackson (Wyoming) in 2015, and a distant pair near Mammoth (California) in 2017.


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