Radio-tagged bees offer new look at landscape
Jeremy Hemberger sits at the desk of his new office and breathes a sigh of relief. “I’m so much more productive over here,” says the UW-Madison entomology graduate student, “it’s so quiet."
Quiet, that is, if you don’t mind that constant buzzing noise.
Hemberger is not alone in his new workspace. He is joined by a team of new lab mates: two live bumblebee colonies. He made the change of scenery to provide space for two enormous, 125-square-foot cages that house his new office companions. Winding up with a superior work environment of his own was an unintended benefit.
Or, perhaps, an act of karma.
Hemberger is on a mission to identify ideal pollinator habitats. His research is part of a widespread effort to address the perils faced by insect pollinators: In recent years, population levels have declined substantially as a result of human activity. A recent study led by Laura Burkle of Washington University found that 50 percent of bee species have disappeared from Midwestern landscapes over the last century.
But pollinator needs are more complex than his own; a quiet, spacious office would not quite cut it. To help untangle the intricacies of their environmental preferences, Hemberger is turning to a sophisticated solution: radio frequency identification, or RFID. By tracking the movement of his bees with radio collars, Hemberger seeks to decipher behavioral patterns that relate to landscape quality.
The end goal is to develop a system that integrates pollinator health into landscape planning. Like many ecologists, Hemberger favors protecting nature for its own intrinsic sake; if the Wisconsin native is not exploring the natural world in his lab, he is doing it from a bike seat, climbing harness or camera lens.
But the implications of the problem he is tackling go far beyond insect wellbeing. Bees are not the only ones in trouble. If pollinator food resources vanish, ours will follow close behind.
Call it another act of karma.
“We’re removing food resources for bees by altering the landscape,” says Hemberger. The trend becomes problematic for human health when we consider the services that bees provide. Recent studies estimate that up to 90 percent of flowering plant species rely on animal pollination, encompassing many important crop species.
“If we want to grow on the scale that we’re growing, we need to explicitly consider managing and conserving for pollinators,” Hemberger says.
Pollination is simply the process of facilitating reproduction in flowers. Just like humans, flowers reproduce sexually with a sperm and an egg. For flowers, pollen is the sperm. For bees, however, it is food.
As bees forage for meals, they inadvertently transport pollen from plant to plant. Many plants are self-incompatible, or unable to reproduce with themselves. These individuals often rely on foraging insects for cross-pollination.
Take apples, for example. Though honeycrisp purists may swear loyalty to their favorite, superior variety, they are failing to see the big picture. Successful fruit set depends on pollen transfer from the other varieties. Pollen from the most sour, mealy apple tree therefore plays an essential role in producing our favorite apple varieties. Pollinating insects provide the essential means of transportation.
But as our population skyrockets, we are manipulating the environment more and more to keep up with food demand. The resulting landscape changes are proving too much for native pollinators.
“We do a heck of a job removing weeds that flower,” says Hemberger, “Plants like dandelion, clover, and thistle, which bees love.” In their absence, bees are left to rely heavily on our crops. Unfortunately, landscape diversity usually plummets in agricultural land to make way for concentrated, uniform growing environments. These conditions often fall short of pollinator needs, creating “food deserts” for many insects.
“Bees require diverse food throughout their life, which is basically from April through October. We have crops that are good for bees, like cranberries and apples, but they only bloom for a couple weeks,” says Hemberger, “After those are gone, there’s nothing."
“Nothing” can be taken literally in this case. Pollination is a driving force behind all agricultural and ecological systems. As the agents responsible for pollination dwindle, global food webs hang in the balance.
Back in his office, Hemberger wields his “bee-vac”: an ordinary hand-vacuum featuring a series of not-so-ordinary customizations, including a sawed off tip, special nozzle, and a reservoir for collecting trapped bees. One of the members of his colonies has escaped.
“I have to go into the cages regularly to water and fertilize the plants,” says Hemberger. With such day-to-day upkeep practices, escapees are just part of the process.
The same can be said about his indoor colonies. Hemberger has ambitious plans to scale up his research. In the long run, his office cages simply serve as a miniature version of a full-scale, outdoor experiment planned for down the road.
But small steps are essential when taking on questions this large. The intimate, indoor setting has unique advantages. Researchers at other institutions have radio-tagged birds and fish, but Hemberger is blazing his own trail with insects.
Working in close proximity with the bees will allow for fine-tuning. After temporarily knocking out the bees with dry ice, Hemberger must race to attach the rice-grain sized radio collars before they wake up. The smallest misstep could result in a crippled bee.
Or, of course, a nasty sting.
Additionally, Hemberger can manipulate the environment inside each cage in ways that would be impossible outdoors. The idea is to start both cages with a maximum amount of flowers and gradually remove plants from one cage while keeping the other constant.
All the while, the RFID logs the foraging behavior of each bee. Hemberger compares it to a tiny highway toll system. A gate records each bee as it enters or exits the nest.
“The only difference is they don’t have to pay,” he says.
Hemberger suspects there is a pattern somewhere in this chaotic jumble of entries and exits. By comparing the amount of floral resources in the cage to the frequency and duration each bee forages, he hopes to give a voice to the bees and let their behavior grade the quality of their surroundings.
As he looks over his data, Hemberger sees more than graphs and spreadsheets. It all coalesces to form something bigger: a push for ecological awareness. His research is as much about people as it is about bees.
“We view ourselves as separate from the natural world, when in actuality we are part of it,” Hemberger says, quickly crediting the idea to his hero, famous UW-Madison conservationist Aldo Leopold.
It only takes a brief glance at our compartmentalized urban, agricultural and rural landscapes to find truth in those words.
In one sense, the effects of our actions on the environment conjure comparisons to karma. But Hemberger would argue it is a matter of shooting ourselves in the foot; we share the landscape in such a way that our activity affects many living things just as theirs affects us. He hopes considering the needs of bees can be a first step in a much-needed shift in the relationship between humans and nature.
Finishing up some final maintenance, Hemberger peels back the screen and enters one of his cages to water flowers. An unused bee suit hangs lifeless in the corner. “I don’t need it,” he says, “We trust each other.”Subscribe to The Daily Cardinal Newsletter