The Sitka bumble bee (Bombus sitkensis) is uncommon in my neighborhood in North Seattle. Over the past three years, I have only observed it twice.

Females resemble the yellow head bumble bee (Bombus flavifrons) but can be distinguished by the light-colored hair (whitish, yellowish, or orange-ish) at the tip of the abdomen. Additionally, the Sitka bumble bee has a shorter tongue (proboscis) compared to the yellow head bumble bee. I have not confidently identified any drones as B. sitkensis; they closely resemble B. flavifrons drones, making differentiation challenging.

At high elevations, I frequently encounter Sitka bumble bees. However, capturing them in photographs can be difficult due to their fast flight.

For more details, refer to page 40 of Bumble Bees of the Western United States.