In the summer of 2024, over 900 enthusiastic Bumble Bee Atlas volunteers spread out across the United States looking for and taking pictures of native bumble bees. Nearly 21,000 bumble bee observations, from across 20 states, have been shared so far this year through Bumble Bee Atlas projects, and submissions are still rolling in. In addition, over 7,800 incidental bumble bee sightings were shared with us by bee-lovers across the country through Bumble Bee Watch!
This incredible community science work is vital for filling data gaps and informing future conservation efforts. Today, we are highlighting some of the exciting finds of this summer’s collective efforts!
American bumble bees spotted taking up residence in an Iowa tractor
In central Iowa, an American bumble bee (Bombus pensylvanicus) queen decided to build a nest inside an old tractor! The nest was detected in early August and is thought to be in a space previously inhabited by rodents. Observations of bumble bee nests are uncommon, and a lot is unknown about what happens inside the nest throughout the season, so any sighting provides valuable data!
Bumble Bee Watch volunteers managed to find the at-risk southern plains bumble bee
The southern plains bumble bee (Bombus fraternus) is known from eastern temperate forests and the Great Plains, but its populations have experienced significant declines over the past decade. Because of its rarity, this is a species we have our eyes on, and we celebrate when any individuals are detected.
So we are thrilled to report that this year, Bumble Bee Watch participants have made 163 verified observations of the southern plains bumble bee so far! The bees were seen in 11 states, from the Carolinas in the east to near Denver, CO in the west. In mid-August, 32 out of 35 bees found during a survey on the Quivira National Wildlife Refuge in central Kansas were B. fraternus! Having volunteer eyes across the country looking for this species is very valuable to its conservation. We are learning more about where populations currently can and cannot be found, the habitats this species uses, and the flowers it relies on.
Is the two-spotted bumble bee moving west?
In North America, many of our bumble bee species are classified as either “eastern” species (known from the east coast to the plains) or “western” species (known from the west coast through the Rocky Mountains). But bees don’t know these boundaries, and sometimes they are found further east or west than previously documented. It is possible that these species have always had larger ranges than we realized, or that ranges are shifting. Either way, it’s exciting (and valuable to our understanding and bee conservation!) when we find species in unexpected places.
One species that surprised us this summer is the two-spotted bumble bee (Bombus bimaculatus). In 2014, when The Bumble Bees of North America was published, records of this species were documented only as far west as central Nebraska and the Dakotas. Since then, it has been seen further west, in Montana, Wyoming, and Colorado.
This year, Bumble Bee Watch observers photographed B. bimaculatus in Wyoming, and Michelle, the Montana Bumble Bee Atlas Coordinator, found another in Livingston, Montana! This is the furthest west it has been seen in that state. These few observations aren’t enough to say for sure that this bee is moving west (and how far it might go), but they are an important step. As our amazing volunteers continue to monitor where B. bimaculatus shows up in the future, we’ll be able to piece together this puzzle.
The yellow-banded bumble bee was sighted again in South Dakota after 70 years!
The yellow-banded bumble bee (Bombus terricola) is another species we have our eyes on. Until relatively recently, it was commonly found all across the northeastern U.S. and southeastern Canada, from Montana and Alberta to the east coast, and along the Appalachian Mountains. However, for years, it hasn’t been seen throughout much of its former range, so finding this bee again has been one of our goals.
This year, Katie Lamke, one of our Midwest/Great Plains Bumble Bee Atlas Coordinators, found a male yellow-banded bumble bee near Aberdeen, South Dakota! This is the first time B. terricola has been seen in eastern South Dakota since the 1950s! Through our Bumble Bee Atlas projects, we are working to document this (and other) species’ limited whereabouts and inform decisions that can protect it in the future.
Join us in learning more about bumble bees!
The Bumble Bee Atlas team at Xerces is proud of the work our incredible network of volunteers has accomplished this year, and we look forward to discoveries that will be made in the future! There is still a lot to learn about bumble bees in North America, their habitats, and the resources they rely on. We are always looking for more people to take part in conserving these amazing animals – now it's your chance to join the team!
- Submit pictures of bumble bees you’ve seen on Bumble Bee Watch
- Become a trained Bumble Bee Atlas volunteer and help find at-risk species!
Amy joined Xerces in June 2024 to coordinate the Mountain States Bumble Bee Atlas in Colorado, Nevada, Utah, and Wyoming. The goal of the project is to engage with agency partners and community scientists to gather data on bumble bee distribution and habitat needs across the region.
