Chasing the rarest bumblebee in the world

A group of Oregonians searches for the disappearing Franklin’s bee.

 

We don’t look like ghost hunters. We’re not dressed in ectoplasm-resistant overalls. We’re out in broad daylight and look pretty normal, not like those glowing-eyed TV guys who are always whispering into night-vision cameras. We’re a typical group of Oregonians gathered at a trailhead, men and women, old and young, with a couple of young kids racing around waving butterfly nets. 

The ghost that we’re chasing is — we hope — not a ghost at all.  It’s a bee. To be specific, it is Franklin’s bumblebee, Bombus franklini, the rarest bumblebee in the world. Always restricted to a tiny range in southern Oregon and northernmost California, the species has seemingly disappeared. Despite many searches, no one has seen a Franklin’s bumblebee since 2006, and experts fear that it is now extinct — a ghost. 

Bombus bifarius, the two-form bumble bee.
Pepper Trail

The search for ghosts — animals and plants that are so rare that they are thought to be extinct — is sadly becoming a common activity for conservation biologists. The most famous search is the decades-long pursuit of the ivory-billed woodpecker. That magnificent bird, a symbol of the primeval forests that once covered Eastern North America, retreated as the forest fell before the axes and torches of the early settlers.

The last undisputed sighting of the species in the United States was in the late 1930s, but tantalizing reports have continued to trickle in, most famously in 2004, when a blurry and much-disputed video was made in the Big Woods of Arkansas. Intensive surveys of the remote swamp were undertaken, only to be abandoned five years later with no further sighting. But still, every year or two comes word of an ivory-bill sighting in some new location. As Emily Dickinson said, hope is the thing with feathers.

Our hunt for Franklin’s bumblebee didn’t require travel into the depths of the wilderness. We just organized a carpool from the town of Ashland up into the nearby Cascade-Siskiyou National Monument on a beautiful sunny day. Once there, we crowded around Robbin Thorp to get our instructions and last-minute pointers.  He’s the University of California expert who was the last person to see a living Franklin’s bumblebee, just a few miles from our meeting-place. 

Dr. Thorp believes that the disappearance of Franklin’s bumblebee populations since 1998 is due to diseases spreading from commercial colonies of bumblebees. Bumblebees are important pollinators of greenhouse crops, especially tomatoes and sweet peppers, but studies show they suffer from higher rates of disease than colonies of wild bees. If they escape greenhouses, which they do occasionally, they can transmit those diseases to wild bees.

In addition to Franklin’s bumblebee, its close relative, the western bumblebee, has also experienced catastrophic declines across the West since the late 1990s. Other wild bumblebee species seem to be doing fine, so the decline of the Franklin’s and western bumblebees can’t be blamed on general factors like habitat loss or wildflower decline.

A group of bumblebee chasers.
Pepper Trail

With this sobering tutorial, we set out on the hunt, bumblebee identification sheets in hand. My team headed south on the Pacific Crest Trail toward a spring where I expected an abundant display of wildflowers, and thus plenty of bumblebees. The flowers were there in abundance — butter-yellow monkey flowers, dark pink checkerbloom, purple coyote mint — and we spent the next several hours netting and releasing yellow-faced bumblebees, yellow-headed bumblebees, two-form bumblebees, fuzzy-horned bumblebees, and indiscriminate cuckoo bumblebees. But no Franklin’s bumblebees. 

The known range of Franklin’s bumblebee covered an area only about 190 miles north to south and 70 miles east to west. It may be that the species simply did not have a large enough population to allow resistance to a new threat to evolve, a situation that, unfortunately, is well documented in both human and animal populations. The western bumblebee, a formerly abundant species with a range covering most of the western United States and Canada, is far more likely to be able to evolve resistance. In fact, two individuals were recorded on Mount Ashland during this year’s surveys, a hopeful sign for that species’ recovery.

But I haven’t given up on the Franklin’s. Its small range is mostly in the Siskiyou Mountains, where there are plenty of little valleys far from roads that have never been surveyed. If you’re out hiking the area someday, and spot a distant figure with a white butterfly net stalking slowly through a field of flowers, well, that might be me. Still hunting for our local ghost, still hopeful, always.

Pepper Trail is a contributor to Writers on the Range, the opinion service of High Country News. He is a writer and naturalist in Oregon.  

Note: the opinions expressed in this column are those of the writer and do not necessarily reflect those of High Country News, its board or staff. If you'd like to share an opinion piece of your own, please write Betsy Marston at betsym@hcn.org.