The photos above are of three female California bumble bees. The bee at the upper left is feeding on flowers of Verbena de la Mina in my backyard. It may be difficult to see, but she has inserted her tongue into a flower to feed on nectar.
I photographed the two bumble bees at the upper right and bottom photo during a California Bumble Bee Atlas point survey that I conducted on the Sunrise Trail last summer. 20 states participated in the Bumble Bee Atlas project in 2024. The Bumble Bee Atlas project is administered by the Xerces Society for Invertebrate Conservation. The project trains volunteers who gather, record and report information via survey work. Volunteers enter the results of their surveys in the platform Bumble Bee Watch.
By following specific protocols while gathering survey data, volunteers help scientists in their research and ongoing efforts to evaluate the status of bumble bee populations in the participating states. In addition to collecting, photographing, and releasing bumble bees, volunteers record specific details about each bee including the floral resource visited. General notes about the survey location habitat type(s), other flowering plants in the area, as well a known or suspected environmental factors are included.
Bombus californicus or Bombus fervidus?
The scientific name for the California bumble bee varies depending on where the bee is observed and who is doing the naming. On the iNaturalist platform, Bombus californicus has a well established presence as a species. However, if one checks the species’ taxonomy tab at iNaturalist, it becomes clear that whether B. californicus qualifies as unique species remains in question. It currently cascades from the subgenus Thoracobombus (which includes many species), to a select, two-species group named Complex Bombus fervidus. The other species in the group is Bombus fervidus.
On Bumble Bee Watch, B. californicus does not exist. To record an observation of B. californicus on Bumble Bee Watch, the closest and only choice available is B. fervidus.
My understanding is that the pending status of B. californicus has to do with a general acknowledgement of the need and desire to gather more information. Biologists and taxonomists who specialize in the study of bumble bees are scientists whose work depends on the careful collection, accumulation and analysis of data. Taxonomy is a living, dynamic, scientific discipline, but I would venture to say that it is not inclined to rush to conclusions.
Studies of B. californicus and B. fervidus1 have included analyses of DNA barcodes; phylogenetics and population genetics; and empirical data. Empirical data analyses have found that where the two species overlap, they may occupy different ecological niches or habitats and manifest with distinct color phenotypes. Some experts believe that the differences between the two species is not enough to declare them as separate species and consider B. californicus to be a subspecies of B. fervidus (NatureServe Conservation Status Factors, Schweitzer, D.F. et al, 2018).
In an online identification guide titled Bumble Bees of Washington State, a group of bumble bee researchers gave an excellent reason to continue to classify them as separate species: Politics.
Our state and federal wildlife conservation laws offer much more protection for distinct species rather than subspecies or ecotypes. By recognizing these as distinct species, it may make it easier to get one of them the protection they deserve when needed (Washington’s Bumble Bees, Rolf, et al. n.d.).”2
In late June I discovered male California Bumble Bees visiting a ‘Pozo Blue’ Salvia shrub in my front yard. These photos are from last summer, taken on two separate days, June 23 and 27. Several of them were flying around the sage for weeks. I am looking forward to seeing a new generation of visitors this summer.
- Schweitzer, D.F. and Capuano, N.A. (2009); Richardson, L.L. (2018). Bombus fervidus. NatureServe Conservation Status Factors (2018). NatureServe Explorer Website accessed on January 17, 2025. ↩︎
- Rolfs, D., Robinson, L., Jennings, D., (n.d.). California bumble bee, Bombus californicus. Washington’s Bumble Bees. Website accessed on January 17, 2025. ↩︎
Hi, Sherrie. I really enjoyed reading your recent post!
While I would expect it will be a challenge to implement the change right now, I hope that the California Bumble receives it’s own distinct recognition sooner than later in order to receive proper wildlife conservation protection.
Although they are not bumble bees, I enjoy watching the honey bees each spring through fall when they visit the lavender blooms of our our Heavenly Cloud Texas sage shrubs as well as the Hidcote lavender that grows along our front walkways.
We keep water nearby for them as well and it’s always a delight to watch. My hope is to see bumble bees pay a visit at some point as well.
Hi Charity, thanks for reading! I’m seeing hummingbirds and honey bees out now that the wind has stopped. Hope it stays that way! Today I saw a large bee from a distance flying across our backyard. It was primarily black. I think it might be a queen bumble bee that recently emerged and is building her nest. I will keep looking for her.