Sarah@sfbg.com
GREEN ISSUE On a rainy afternoon in April, I’m standing on an abandoned military base on Alameda Island counting bees on a wild rosemary bush. In the three minutes I’ve been standing here, I’ve spotted five large, furry bumblebees, flitting from flower to flower, performing the function that keeps the whole ecosystem buzzing.
But the honeybees I often see here are absent. I’m not surprised. As I learned from Bernd Heinrich’s Bumblebee Economics (Harvard University Press, 1979) bumblebees are tundra-adapted insects that are better able to forage at low temperatures than sun-loving Italian honeybees.
I’ve been obsessed with bees for years. My sister says it began when I got stung on the bum as a toddler. My daughter says it started the day we rescued a swarm of half-drowned honeybees that had gotten stranded in high winds on a beach in Santa Cruz. All I know is that my bee obsession really bloomed when we lived on a lavender farm on the north coast of California and I found bumblebees asleep on the lavender, at night.
A beekeeper on the farm explained that, unlike honeybees, bumblebees don’t form permanent colonies. Instead, they nest in empty mouse holes and form small social groups that die out each fall. The bees sleeping on the flowers were probably male, he added; they tend to be lazier, while the females do most of the work.
He told me that only the young pregnant bumblebee queens hibernate in the fall, emerging alone the next spring to start new colonies. There are more than 4,000 species of native bees in North America. Some are the size of ants; others are territorial and drive other bees off the flowers they guard. Most are solitary, nonaggressive loners, and some aren’t that busy at all.
Curious, I bought a book about beekeeping from a clerk who told me his father once kept bees in Oakland. “Urban honey is the best,” he said, explaining that urban gardens often contain unusual and diverse collections of plants. “City bees have far more exotic choices of nectar.”
Fast-forward to the present and it seems that the general public also has taken a much more active interest in bees, particularly since 2006 when colony collapse disorder decimated honeybee populations, triggering warnings of a coming agricultural crisis and potential devastation to the ecosystem.
Scientists estimate that bees pollinate nearly three-fourths of the world’s flowering plants. These plants provide food and shelter for many species of animals. A 2008 survey by the U.S. Department of Agriculture shows that 36 percent of the 2.4 million hives in the U.S. have been lost to colony collapse disorder, which translates into billions of honeybees.
Some species of bumblebees also are vanishing. Robbin Thorp, professor emeritus of entomology at UC Davis, blames their disappearance on commercially reared bumblebees that are imported to pollinate hothouse tomatoes and then escape into the wild, where they leave pathogens on flowers (see “Buzz Kill,” 01/27/10).
But amid such big news, I’m still keeping a diary of notes on bees and focusing on my own backyard on Alameda Island, wondering how I can attract more bees. Xerces Society for Invertebrate Conservation heeded Thorp’s thesis and petitioned to stop the cross-country movement of bumblebees, but the Portland, Ore.,-based group has also produced handy pocket guides to help people like me identify bumblebees in the field.
So far I haven’t spotted the missing Western bumblebee, Bombus occidentalis. But I did see a bumblebee queen spiraling through a Potrero Hill garden on a mild day in early January. Reached by phone, Heinrich, professor emeritus of the biology department of the University of Vermont, told me that the queen would retreat into her underground hole when the weather got cold and wet again, which it soon did.
When he was writing Bumblebee Economics, which explores biological energy costs and payoffs using bumblebees as the model, Heinrich studied Bombus terricola, the yellow-banded bumble bee that was plentiful around Maine bogs in the 1970s.
“I could see dozens all at once. But since then, for years I didn’t see any at all, and since then I’ve only seen a few,” Heinrich said “Nobody figured out what happened.”
Gordon Frankie, professor and research entomologist at UC Berkeley, told me he’s happy to see the increased interest in urban bees. “People have begun to recognize that bees have a major role to play in agriculture,” Frankie said, as he and Rollin Coville, who has a doctorate in entomology from UC Berkeley and a passion for photographing insects, showed me around the experimental urban bee garden they created in 2003 at the edge of a field in downtown Berkeley.
“Bees love blues, purples, pinks, and yellows,” Frankie said, explaining that bees can see ultraviolet hues but not red flowers as we observe bees busily foraging on a blue lilac bush.
He also said bees love hanging out in open meadows where the sun shines and where they can see the flowers. “In the forest is no damn good if you’re a bee,” he said.
In July 2009, Frankie, Coville, and Thorp published an article in California Agriculture that outlined the results of bee surveys in gardens in Berkeley, La Canada Flintridge, Sacramento, San Luis Obispo, Santa Barbara, Santa Cruz, and Ukiah.
“Evidence is mounting that pollinators of crop and wild land plants are declining worldwide,” they wrote. “Results indicate that many types of residential gardens provide floral and nesting resources for the reproduction and survival of bees, especially a diversity of native bees. Habitat gardening for bees — using targeted ornamental plants — can predictably increase bee diversity and abundance and provide clear pollinator benefits.”
Frankie and Coville also helped produce a 2010 native bee calendar that features Coville’s photographs of bumble, squash, mason, carpenter, leafcutter, mining, wool carder, cuckoo, and ultragreen sweat bees, plus tips on how to attract these pin-ups by planting a variety of bee-friendly plants, avoiding pesticides, and refraining from over-mulching.
Researchers have observed almost 50 species of native bees at UC Berkeley’s bee garden, out of 85 species recorded citywide. UC Berkeley’s urban bee gardens’ Web site, (www.nature.Berkeley.edu/urbanbeegardens) notes that bees have preferences for gardens as well as flowers.
“Gardens with 10 or more species of attractive plants attracted the largest number of bees,” the Web site states, cautioning people against hanging around plants too long. “If an observer spends too long in one place hovering over the same patch of flowers, the bees will gradually begin to move on to other flowers where they won’t be bothered. To facilitate counts, it is sometimes a good idea to create little paths through the garden so that all patches are accessible to the observer.”
Here in California, high real estate prices have led to the increased paving over of bee habitat. And bees have come under additional stress in the wake of a 2006 E. coli outbreak that sickened more than 200 individuals and resulted in at least three deaths on the Central Coast. Growers have since been pressured to eliminate hedgerows, wetlands, habitat, and wildlife around farms.
But as a February 2010 Nature Conservancy report on food safety and ecological health notes, “certain on-farm food safety requirements may do little to protect human health and might in fact damage the natural resources on which agriculture and all life depend.”
These concerns have a direct, if hidden, impact on Bay Area residents, whose food supply comes almost exclusively from outside urban limits. Take San Francisco, where crop production consists of $1 million worth of orchids, flower cuttings, and sprouts on two acres of land, according to a 2008 Department of Public Health report.
Missing from that equation is the honey that local bees produced. As San Francisco beekeeper Robert MacKimmie recently noted, mites hit his hives hard in 2009. “And the summer and fall were pretty brutal since we were in the third year of drought,” MacKimmie said.
He hopes El Nino-related rains will be good for this year’s bees: more water means more flowers for bees, which rely on nectar and pollen to sustain themselves and their developing brood.
MacKimmie doesn’t have a garden and uses other people’s yards to keep his bees. “The honey serves as rent,” he said, noting that he only places two hives in each yard to disperse the bees in more equitably and sustainably. He points to the work of Gretchen LeBuhn, a San Francisco State University professor who started the Great Sunflower Project in 2008, as a fairly easy way to gather information about bee populations.
Reached by e-mail, LeBuhn said her project has more than 80,000 people signed up to plant sunflowers this year. “Participants create habitat by planting sunflowers and then contribute data to our project by taking 15 minutes to count the number of bees visiting their sunflower,” she wrote.
“The Great Sunflower Project empowers people from preschoolers to scientists to do something about this global crisis by identifying at risk pollinator communities,” LeBuhn said. “By volunteering to collect data as a group, these citizen scientists provided huge leverage on a minimal investment in science and created the first detailed international survey of pollinator health and its implications for food production.
“Getting this kind of critical scientific data at thousands of locations using traditional scientific methods would cost so much money that it is untenable,” she added.
LeBuhn encourages people to submit their bee count data at www.greatsunflower.org, which recommends growing bee balm, cosmos, rosemary, tickseed, purple coneflowers, and sunflowers. Unfortunately her data shows that “at least 20 percent of the gardens are getting very poor pollinator service.”
The public is encouraged to visit the UC Berkeley bee garden in May when public tours begin. But you might want to brush up on your Latin, the language experts speak when they hang out with the bees.
Coville saw a mason bee land on a lavender-flowered sage and said, “I think I just saw an Osmia on a Salvia mellifera!”
Frankie smiled at me and said, “It’s bee talk.”