Bringing back the buzz

Post by Jen Berlinghof

All summer long, swaths of wild bergamot (Monarda fistulosa) quake in the presence of thousands of native bumble bee wings beating away. These pollination dynamos use a technique called buzz pollination, vibrating their bodies to trigger nearby flowers to release pollen. At the Lake County Forest Preserves in northern Illinois, a similar buzz of excitement arrived in summer 2020 when staff spotted the federally endangered rusty patched bumble bee (Bombus affinis) at Greenbelt in North Chicago.

Fast forward to summer 2021. The hum continues to reverberate after multiple sightings of this keystone species were documented across the county from Flint Creek to Wadsworth Savanna in Wadsworth. While summer’s the height of hive activity, the shoulder seasons—usually defined as May, June, September and October—might be key to the success of the rusty patched bumble bee. This is partly due to the timing, or phenology, of the species’ lifecycle. It’s one of the first bees to emerge in spring and the last to enter hibernation in fall.

A worker, or male, rusty patched bumble bee (Bombus affinis) sits atop mountain mint. Photo © Dan Mullen.
A rusty patched bumble bee (Bombus affinis) sits atop mountain mint. Photo © Dan Mullen.

While the rusty patched bumble bee became the first federally endangered pollinator in 2017, it’s not the only native bumble bee in peril. Of North America’s 4,000 native bees, many are declining rapidly due to habitat loss, increased pesticide use, disease, and climate change. A pollinator poster child, the rusty patched bumble bee’s populations have fallen more than 87% over the past 20 years. And according to the U.S. Fish and Wildlife Service, it flies the skies of fewer than 1% of its historic home range.

Native bees are critical to native wildflower pollination and the diversity of the food supply for wildlife and humans alike. Which is why there’s a vast conservation effort happening in natural areas, backyards and cities across North America to save the rusty patched bumble bee from extinction.

Wildlife biologists, restoration ecologists, and community scientists monitor and record sightings using crowd-sourcing sites such as BeeSpotter and Bumble Bee Watch to share data. The majority of information involves sightings during late summer and early fall. This is when female workers—their pollen-laden hind legs resembling yellow leg warmers—and male drones can be captured and put on ice, temporarily slowing them down to allow easier identification. After gathering data, bee researchers release the insects so they may continue on with food collection and sperm donation to the betterment of their hives.

In July 2020, Stewardship Ecologist Kelly Schultz spotted this rusty patched bumble bee at Greenbelt in North Chicago, causing a flurry of excitement among staff, residents and local ecologists. Photo © Lake County Forest Preserves.
In July 2020, Stewardship Ecologist Kelly Schultz spotted this rusty patched bumble bee at Greenbelt in North Chicago, causing a flurry of excitement among staff, residents and local ecologists. Photo © Lake County Forest Preserves.

And yet researchers struggle to learn more about how those hives actually function. They know the lifecycle of native bumble bees is unique—the entire colony dies out in late fall, leaving behind only a queen, who’s already been fertilized, to overwinter. It’s not totally clear where the vagabond queen hunkers down, but new research leads scientists to suspect she heads into forests to slumber in the crevices of trees. Come spring, she emerges to establish a colony in old mammal burrows or the cracks of tree trunks.

The rusty patched bumble bee is one of North America’s 4,000 native bee species. Photo © Dan Mullen.

The queen typically times her spring emergence to coincide with the blooming of ephemeral woodland wildflowers. These early-blooming plants provide a much-needed energy boost for the queen, necessary for her work setting up the hive after a long winter dormancy.

But a new study shows evidence of a decline in spring woodland wildflowers, along with an increase in prairie and grassland flowers the rusty patched bumble bee feeds from during summer and fall. Researchers hypothesize this drop in woodland spring blooms might contribute to the fall in bumble bee populations by limiting the queen’s ability to garner enough energy to start a colony. There’s also evidence of climate change implications as the flowering times of plants may start to shift, potentially misaligning the queen’s needs with the availability of nectar and pollen in early spring.

A rusty patched bumble bee feeds on nectar from a wild bergamot (Monarda fistulosa) plant. Photo © Lake County Forest Preserves.
A rusty patched bumble bee feeds on nectar from a wild bergamot (Monarda fistulosa) plant. Photo © Lake County Forest Preserves.

With its long colony life stretching from April through September, the endangered rusty patched bumble bee requires nectar and pollen from a variety of native flowers in prairies and grasslands over spring, summer and fall. Additionally, it needs the safe haven of a healthy woodland to support the overwintering queen. Habitat restoration of these vital ecosystems in the Forest Preserves and other natural areas is critical to help ensure this species survives and thrives in Lake County.

You can help, as well! Plant bee-friendly native plants, avoid the use of toxic pesticides and chemical fertilizers, and contribute to community science monitoring programs such as BeeSpotter or Bumble Bee Watch. Let’s all keep the buzz of native bumble bees going!

Ghost of the prairie

Post by Jen B

Many years ago, while hiking through a prairie at dusk, I saw a stalk of delicate white flowers. They seemed to rise and hover above the surrounding plants like a group of little dancing ghosts. This was the first and last time I ever saw an eastern prairie fringed orchid (Platanthera leucophaea). Due to its dwindling numbers and hidden habitats, this rare plant has reached almost mythical status—a holy grail of sorts in the Midwest. We’re thrilled that this endangered native orchid seems to be gaining a foothold in the Lake County Forest Preserves, which are home to some of the largest remaining populations. Just this month, one of our restoration ecologists discovered an orchid in bloom (photo below). It was found at one of the preserves known to provide habitat for this species but is the first documentation of a population at the site.

PWF_orchid_lcfpdpic

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Red admirals at attention

Last week while visiting Lyons Woods, I noticed that a large patch of garlic mustard was quivering. When I got closer, I found that it was not the breeze making the plants sway, but rather a huge group of red admiral butterflies (Vanessa atalanta) flitting from flower to flower. In many areas, all you have to do is walk out your front door to witness the population explosion of these ubiquitous butterflies that is sweeping the northeastern United States this spring.

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Ground’s abuzz

During a training hike for volunteer nature guides last week, a fellow naturalist pointed out a series of pea-sized holes in the ground. I walk along this same trail regularly and had never noticed them. As our group stooped around these holes, shivering on this cold but sunny spring morning, a tiny head crept slowly out of the one of the holes. It was the head of a mining bee! Continue reading