California Statewide Survey

With the success of the monitoring in Berkeley and other nearby cities, the urban bee lab has extended their research beyond the Bay Area to include several more locales throughout the state of California. The goal is to document and explore the diversity of native bees from Northern to Southern California. We are curious to see if a flower type in a garden in Ukiah attracts the same kinds of bees as the same flower in a garden in Santa Barbara and beyond. Do the same bees in southern California prefer the same flowers as the same bees in northern California? This research seeks to find some of these answers.

The survey began in 2005 and is still ongoing. We visit each site monthly, starting at the beginning of the bees’ season, which is usually early spring, and continue until the end of the season in late fall. Seasonality between the sites is variable, as is rainfall, so we document the flowering times for all flowers at each site carefully. Good “bee days” are also sought out when visiting each site in order to provide the best results. The weather should be warm and sunny with little to no wind in order to provide the best conditions to view and record the bees.

From North to South the cities we have chosen to sample are: Ukiah, Sacramento, Berkeley, Santa Cruz/Soquel, San Luis Obispo, Santa Barbara, and La Canada Flintridge (near Pasadena). These cities were selected because of their diverse flowers and gardening cultures. Some of the gardens in these cities include arboreta, home gardens, community gardens, and even cemetery gardens! Other urban sites have been explored, like Paso Robles and San Diego, but the gardening culture is so different that suitable gardens were not found. Redding and Riverside have just been added to our statewide survey in 2009 and are already showing good bee diversity.

In order to make comparisons from Northern to Southern California we selected 31 target plant species to monitor. There are both native and non-native flowers on the list, and they have been chosen because of their attractiveness to bees and because they are widely planted across the state. Some of the flowers we monitor include CA Poppy, yarrow, catnip mint, Santa Barbara daisy, lavender, sunflowers, and several different salvias (native and non-native). The flowers are observed according to our “Bee Monitoring Protocol” see and collections are made so that we can correctly ID all the bees.

For almost all target plant types, the same characteristically associated bee groups were found in each of the above 7 cities. This was especially noticeable with native bees. The two most attractive plant families were Asteraceae (which provide pollen and nectar) and Lamiaceae (which provide nectar). With this kind of information, gardens can be planned with predictable relationships between bees and ornamental plants.

Each year we continue to add new bee species to all of our urban sites. To date we have found that La Canada Flintridge boasts the largest number of bees at 94 species, followed by Ukiah and Berkeley. The research is ongoing and is being used to write a UC Press field guide on garden bees of California and their flowers. A second related book is in the planning stages and will focus on a step-by-step approach to designing and implementing a bee habitat garden. The book will also discuss how to monitor bees and how to use bee gardens for a variety of purposes ranging from environmental education to conservation to scientific inquiry.