Endangered bumblebee sighting has campus buzzing

Something was different. Laura Walter had examined the plants and insects at the Tallgrass Prairie Center countless times. But this stood out.

In most ways, it was a normal August day. The prairie was alive. The tawny orange of the monarch butterfly wing fluttered across the vibrant magenta-purple of meadow blazing star plants, one of many native vegetation spread throughout the center’s 65-acre campus. All manner of bumblebees alighted on flowering plants, carrying pollen from stamen to pistil. Waist-high grass rippled in the wind.

It was a familiar scene for Walter, the center’s native plants technician. She roams the center’s multiple seed plots most days of the summer, checking on the growth and reproductive stages of the native prairie plants and monitoring for potential problems, such as weeds, pests and diseases.

Plants are her career, but insects have been one of her passions since she was 10 years old starting out in the youth development organization 4-H. She’s a keen observer of the behavioral eccentricities of the center’s tiny, winged population. But on that August day, while checking a plot of spotted Joe Pye weed, she saw something new.

“When you get very familiar with certain things in your environment, the ones that are different pop out,” Walter said.

It was a bumblebee that caught Walter’s eye. And something was different. When she looked closer, she noticed the difference was a band of rusty color across the bee’s abdomen. 

“That’s when I started to get excited,” Walter said.

Walter had spotted a rusty patched bumblebee. It is a pollinating machine – a species of bumblebee that was once widespread across the Eastern United States. But over the past few years, the population has plummeted, decreasing by an estimated 87 percent. And biologists aren’t sure exactly why. It’s now listed as endangered by the U.S. Fish and Wildlife Service, just one step away from being extinct in the wild. It's the first bumblebee species the wildlife service has listed.

Because of this, it was a species of bumblebee that Walter never expected to find. But here it was, casually buzzing around flowers less than a mile west of the UNI-Dome.

That moment would reverberate across the University of Northern Iowa. The presence of this tiny, off-colored pollinator simultaneously validated years of native prairie cultivation at the Tallgrass Prairie Center and created exciting learning opportunities for UNI biology students.

A “gamechanger” for conservation education

News of Walter’s discovery spread quickly through UNI’s conservation and biology community. When Laura Jackson, director of the Tallgrass Prairie Center, heard about it, the first thing she thought of was the students.

The rusty patched bumblebee. Photo courtesy of Laura Walter.
The rusty patched bumblebee. Photo courtesy of Laura Walter.

“It’s an incredible opportunity for UNI students,” Jackson said. “Students will get a hands-on opportunity to learn about the Endangered Species Act, and how it’s carried out on the UNI campus. That’s incredible. That didn’t exist before.”

Associate Biology Professor Mark Myers said he would make the bumblebee’s discovery the focal point of his instruction of the Endangered Species Act in his Biodiversity Conservation Policy and Evolution, Ecology and the Nature of Science courses.

“I hope to engage the students in what we can do as an institution to make sure we’re following the law, and what we can do to provide better conditions for threatened and endangered species,” Myers said. “It’s exciting.”

He has already taken students out to search campus for the bumblebee and had some intriguing, though unverified, sightings.

Little insect, big impact

They may be small, but, ecologically speaking, bumblebees are kind of a big deal.

As they harvest nectar, bees also help pollinate plants. Pollination enables plants to produce seeds. Seeds grow into much of the foods that we, and other animals, eat.

"With very few exceptions, the fruits and vegetables we consume rely on bees. A healthy human diet depends on pollinators,” Jackson said. “If you don’t have pollination services, it’s not just affecting the plants, it’s affecting everything that relies on those plants. Your ecosystem would crumble, basically.”

Now, this is not to say that the rusty patched bumblebee alone does all this work. There are 46 species of bumblebees in the United States, Jackson said, not to mention the pollination done by hummingbirds, butterflies and moths.

But the rusty patched bumblebee is notable in that it’s actively pollinating for one of the longest times – from late March to October. It’s an irreplaceable part of the ecosystem.

The problem is the rusty patched bumblebee has all but disappeared.

“They’re almost gone”

The decline of the rusty patched bumblebee was stunningly sharp. It happened so fast it was barely observed.

“They disappeared before we even knew they were declining,” said Ai Wen, an adjunct professor of biology. “We’re at the point that we know they’re almost gone.”

While population decline is difficult to estimate for insect populations, research has posited that rusty patched bumblebees have decreased by 87 percent, Wen said.

Biologists have yet to pinpoint the exact reason for the decline. It’s likely a confluence of factors, including pesticide and herbicide use, disease and climate change.

But one thing is certain: One of the causes is a dramatic loss of bumblebee habitat – the native prairie that once covered about 85 percent of Iowa.

As mentioned before, rusty patched bumblebees are active for a longer period than most other bumblebees. They pollinate plants from March to October. To do this, they need a wide variety of plants that flower throughout the bee’s active periods. Native wild prairies had this diversity. The current landscape of Iowa – dominated by corn and soybean fields - does not.

Enter the Tallgrass Prairie Center.

The root of the issue

So, how much native prairie has Iowa lost?

In a percentage, 99.9. That's one one-thousandth of the original prairie," Jackson said.

It’s the center’s mission to establish, protect and restore native vegetation and tallgrass prairie habitat. They do this through efforts like the Integrated Roadside Vegetation Management program, which utilized a federal grant to distribute seeds to county governments. Since 1999, this has resulted in about 60,000 acres of native prairie being planted along county roads. The center also works with farmers to convert small portions of their crops to prairie.

Prairie vegetation plays an important role in the ecosystem, and it’s not always in the beautiful flowers that the rusty patch bumblebees love. One of its main functions happens below the soil, where the prairie plants’ roots grow deep.

A seed plot at the Tallgrass Prairie Center.
A seed plot at the Talgrass Prairie Center.

Many of the problems plaguing Iowa, such as tainted agricultural runoff and flooding, could be mitigated with more prairie vegetation, Jackson said.

That’s because the prairie roots act like a sponge, soaking up water - whether it contains agricultural chemicals or not. This keeps water from soaking through the ground until it hits farmer’s tile drainage systems, where it runs unimpeded into the river, Jackson said.

Prairie roots can play this role all year. Corn and soybeans, which are only planted in the summer, cannot.

“It’s a real challenge to have a healthy ecosystem, clean water and not having flooding when we have a landscape with plants whose roots are only active for a few months out of the year,” Jackson said. “It’s not the farmers fault, they’re doing everything they can. Without those roots in the ground, there’s only so much you can do.”

Of course, prairie vegetation also provides vital habitat for a variety of insects and burrowing animals. The center works hard to create this habitat on their 65-acre campus.

So, in that sense, the presence of the rusty patch bumblebee is a sign they’re doing something right.

“It is tremendously validating,” Jackson said. “It’s also validating UNI’s management of the property. We have woodlands and preserves all over campus. All those things are contributing to habitat.

“That bee is giving us the thumbs up.”