The western bumble bee, Bombus occidentalis, is an uncommon visitor in Boulder. This one was spotted foraging on black berry flowers in the Shakespeare Garden at CU-Boulder. This species is thought to be in decline in parts of its range so it's a welcomed sight just outside the Museum of Natural History!
I am a Postdoctoral Associate at CU-Boulder and have lead a number of projects studying patterns of native bee diversity in Colorado. Please enjoy your visit and contact me if you have any questions.