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Tamalpais Bee Lab

Photo: Sara Leon Guerrero

What is the Tamalpais Bee Lab?

The Tamalpais Bee Lab is a One Tam effort to monitor and understand more about Mt. Tamalpais' local wild bees and other pollinators. 

From 2017-2022, in collaboration with Dr. Gretchen LeBuhn and her lab at San Francisco State University, we completed an initial 2017 survey of Mt. Tam’s wild bees. This work stems from One Tam's Peak Health effort to understand the health of Mt. Tam's natural resources, where we saw we needed to learn more about the region's pollinators. 

The initial survey yielded remarkable results, recording 32 genera and 122 bee species from 20 sites managed by Marin Water and California State Parks. You can hear more about these results from Dr. LeBuhn and Dr. Lisette Arellano, One Tam’s Community Science Sr. Program Manager.  We then expanded the survey to other One Tam partner lands in subsequent years, and most recent results were presented by Sara Leon Guerrero, Community Science Program Manager at our 2022 One Tam Science Summit, which you can view here.

Our team has been busy preparing the collections that our volunteers helped us manage over the last year to send to the USDA for species identification. For 2024-25, after a lot of planning, we are transitioning the Tamalpais Bee Lab to a different set of targeted monitoring efforts, and offering new volunteer opportunities! 

What's Happening Now?

What is the new phase of the Tamalpais Bee Lab? 

Our new phase is focused on better understanding local bee communities, gathering information to inform future targeted monitoring studies, and contributing local data to broader efforts seeking to study and protect native bees. To achieve these goals, this year we are taking part in the California Bumble Bee Atlas and nationwide Ground Nesting Bee surveys, and starting a new effort – the San Francisco Bay Area Leafcutter Bee Search Party. Each of these is described in more detail below, and there are ways for volunteers to get involved in each!

  1. The California Bumble Bee Atlas (CABBA) is a collaborative community science effort, coordinated by the Xerces Society of Invertebrate Conservation and California Department of Fish and Wildlife, to track and conserve California’s native bumble bee species and contribute to the global understanding of bumble bee distributions.

  2. Ground Nesting Bee surveys (GNBee) is a recent community science effort launched by the Danforth Lab at Cornell University to better understand and protect nests of ground-nesting bees. Approximately 75% of all native bee species nest in the ground and yet we still know relatively little about their requirements and preferences for nesting habitat. By participating in this project, community scientists can help fill critical knowledge gaps on where and when bees nest so researchers and land managers can better work to protect and promote them in our public lands.

  3. The San Francisco Bay Area Leafcutter Bee Search Party is a new effort to find Trachusa gummifera, a rare endemic bee species only known from a few historical records, which has been missing for decades and was last seen in the Mt. Tam region. Despite being identified as a species of special concern by the CA Department of Fish and Wildlife, little is known about this species' biology and ecology, and there have been no recent efforts to learn more. The rarity and lack of knowledge of T. gummifera and its habitat requirements make it difficult to assess its conservation status and needs. Conducting dedicated surveys to document its continued existence and identify habitat associations will help fill these knowledge gaps and will provide data for future research and management.

How are surveys conducted?

Each survey has a different protocol that is determined by the study design, but in general each survey involves: 

  1. Visiting a site designated by One Tam agency partners as an area of interest. 
  2. Searching for bees or their nest sites. 
  3. Documenting the bees and/or nest sites with high quality photographs. 
  4. Uploading the photographs and metadata to a portal for identification by experts.

If you would like to know the details of the CABBA and GNBee surveys, you can find more information on their websites: 
•    CABBA – About the Project and Point Survey Protocol 
•    GNBee – About the Project and Reporting Observations

Get Involved!

Community science volunteers play a critical role in this work! Volunteers can participate in these efforts in two ways, and we have several dates on the calendar for Summer 2024:

  1. Attend a regularly scheduled TBL event and conduct surveys at predetermined sites with One Tam staff and other volunteers.
  2. Attend a TBL training in the spring and adopt a predetermined site to conduct surveys by yourself or with your family and friends.


Please note that locations for these events vary - please see the table below for a list of dates and locations. The registration link (above) is the same for all dates.

Friday, May 17
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Old Mine Trail, Mt. Tamalpais State Park, Mill Valley
Saturday, May 18
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Millerton Point, Tomales Bay State Park, Inverness
Friday, May 24
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Rush Creek Preserve, Novato
Saturday, May 31
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Saturday, June 1
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Friday, June 7
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Saturday, June 8 
CA Bumble Bee Atlas training with Dr. Leif Richardson, Xerces Society
Friday, June 14
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Saturday, June 15
CA Bumble Bee Atlas & Ground Nesting Bee Surveys
Friday, June 21CA Bumble Bee Atlas & Ground Nesting Bee SurveysTBD
Saturday, June 22CA Bumble Bee Atlas & Ground Nesting Bee SurveysTBD
Friday, June 28CA Bumble Bee Atlas & Ground Nesting Bee SurveysTBD
Saturday, June 29CA Bumble Bee Atlas & Ground Nesting Bee SurveysTBD

 If you have questions, please email 

Staff and volunteers participate in a CA Bumble Bee Atlas training. Photo: Kelly Sullivan for the Parks Conservancy.
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