A new rusty patched bumblebee sighting in Marion signals that habitat conservation efforts could be helping the federally endangered species.
Monarch Research, a nonprofit in Linn County, works to incorporate native habitat in rural and urban settings. Research Station Manager Danielle Holthaus said those efforts benefit a lot of pollinators — not just monarch butterflies.
“A few weeks ago, as our team was wrapping up, just typical end of day chores at the research station, I noticed that there was a bumblebee over by a patch of flowers near the research station building in one of our other larger prairies,” Holthaus said.
Holthaus has experience with bumblebees. She used to work with Iowa State University surveying the state for the rusty patched bumblebee, which has been on the endangered species list since 2017. The rare pollinator has all but disappeared from most of its historic habitat across the Midwest, Northeast and Canada. Researchers estimate it now lives in a single digit percentage of that range.
Even with her expertise, Holthaus wasn’t certain what she was looking at.
“I automatically took a photo of it, and then I sent it to someone at the Iowa Department of Natural Resources just to get photo ID verification,” she said. “I wanted to confirm that it was indeed a rusty patched bumblebee, and they got back to me and said that's what it was.”
This isn’t the first time a rusty patched has been spotted in eastern Iowa. In 2024, a conservationist discovered an entire nest in her backyard in Iowa City. In 2021, a wildlife expert photographed the bee in Ames. Monarch Research supporter Ann Hammond saw a rusty patched pollinating her flowers in 2021, a few years into her journey of restoring native habitat on her 12-acre property.
The U.S. of Fish and Wildlife Service considers many parts of eastern Iowa “high potential zones,” which are places a rusty patched bumblebee is most likely to be.
“This was Monarch Research's first sighting, which is super exciting for us,” Holthaus said. “But I think this speaks to the wider finding that the habitat that we're providing them is clearly bringing them in and supporting them.”
Holthaus doesn’t think this is an isolated finding. But she said tracking down a bumblebee nest is no easy task. Like honeybees, bumblebees are social and form colonies. Unlike honeybees, bumblebee nests are underground. Holthaus said bumblebees like to repurpose old rodent burrows.
“I've stumbled across a bumblebee nest before — not a rusty patched nest — and if you get close, you'll see some workers patrolling around the nest,” Holthaus said. “If you get really, really close, you can hear them buzz from below ground.”
She said her team will try to figure out if there’s a rusty patched nest on their property.
“It's going to be difficult, and I think just a single sighting of a rusty patch is just still a very encouraging sign,” she said.
Holthaus hopes this sighting will inspire anyone who owns a little bit of green space to bring some native habitat to their property. She said the bees rely on both healthy prairie and woodlands.
“Community action is really important,” she said. “Hopefully, it does empower other people around the state to create native habitat that can support both this species — this imperiled rusty patched bumblebee species — but also supporting other important pollinators in the process.”
But there’s one more thing Holthaus asks of anyone wanting to support native pollinators.
“If you provide the habitat, and they do visit, it's important to be on the lookout for them,” she said. “If you're not looking for these species, they could go undetected, even though you've planted the habitat for them. So I always like to encourage everybody to take a minute to go out and see what's visiting the habitat that they've helped restore, because every single detection is super important.”
