Shelley Arrowsmith has nearly 1 million honey bees — imports from Europe — spread out among 15 hives on her Sonoma property. On Saturday, the self-professed bee-lover and a team of volunteers searched for other types of bees, some of the 1,600 species that are native to California.
Net in hand, Arrowsmith stalked a hairy, yellow-faced bumble bee that had alighted on a purple agastache flower. With a deft flick of the wrist, she scooped the bee into the net and took it to Gordon Frankie for inspection.
“This is a beauty,” said Frankie, a conservation biologist with the University of California, Berkeley.
This fortunate bee was let go. Some of its captured cousins were put into jars, pinned and studied.
“I've been fascinated by how bees behave,” said Arrowsmith, the volunteer coordinator. “Since they are born, they know what their job is going to be and they just do it.”
The annual native bee count in Sonoma provides valuable data to researchers at UC Berkeley, who are able to glean information about the health of an ecosystem from the diversity of the bee population. They plan to publish their results in the journal Conservation Biology. Preliminary information suggests that native bee species have declined in the last year, which researchers attributed to the drought that has parched the region for two straight summers.
“The drought is affecting bees,” Frankie said. “The drought affects plant life which in turn do not produce as much pollen.”
Colony collapse disorder, a phenomenon in which European honey bee colonies abruptly disappear, does not affect the native species studied by the group. Another well-known species, the Africanized honey bee, or “killer bee,” that has spread into the United States from South America seems to have stopped in Southern California and is not found in Sonoma County.
The bee count is in its fourth year of a 10-year study. Volunteers return each year to the same three Sonoma parks on the last Saturday in June to identify as many bee species as possible. In the past two years, they have found 62 species, which is pretty good for an urban area, according to Jaime Pawelek, a UC Berkeley research assistant.