# Innovative Approaches to Monitoring Honeybee Behavior
Written on
Chapter 1: The Quest to Understand Honeybee Behavior
In the summer of 2009, residents of Möggingen, Germany, might have noticed a peculiar sight among the local bumblebee population. Some of these bees were equipped with small metallic packs and long antennas, buzzing from tree to tree and flower to flower. A scientist quietly observed their activities.
The bees were fitted with miniature transmitters capable of detecting signals over distances exceeding a third of a mile. This groundbreaking work by Dr. Martin Wikelski and his team from the Max Planck Institute for Ornithology marked the first successful tracking of bumblebees as they explored their environment. The findings revealed that these insects could travel as far as 1.5 miles, covering over 100 acres and frequently returning to specific trees or flower patches for rest and nourishment. Given that a bumblebee weighs approximately 300 milligrams, carrying the transmitter was akin to a 150-pound individual toting a 100-pound weight daily.
These backpack-clad bumblebees not only provided a fascinating visual but also presented a potential solution to the pressing issue of colony collapse disorder (CCD), a phenomenon devastating honeybee populations. Each year, CCD wipes out about one-third of commercial honeybee colonies in the United States. The most recent winter saw a staggering 45 percent of U.S. beekeepers witnessing their bees abandoning hives, a notable 78 percent increase from the prior year, as reported by a USDA-funded survey.
In a recent discussion, Wikelski highlighted that utilizing radio telemetry to track honeybees could help identify areas where these insects encounter viruses, bacteria, mites, and pesticides that contribute to their declining numbers. By observing their flight patterns, researchers could detect behavioral changes and potentially uncover the reasons behind their deaths. “The bees would inform us about their experiences and surroundings,” Wikelski explains. “This information could be instrumental in their protection.”
The first video titled "Tracking Honey Bee Growth From Birth Until Death" by Michael Smith discusses the life cycle and challenges faced by honeybees, shedding light on the significance of monitoring their behavior.
Section 1.1: The Challenge of Tracking Small Insects
Current radio tracking devices are not yet small or light enough for honeybees, which weigh approximately 120 mg—only slightly heavier than a raindrop. However, Wikelski, who previously advanced the use of radio tags for monitoring cicadas and dragonflies at Princeton, believes that tracking technology is evolving rapidly. He anticipates that transmitters will soon be compact enough for honeybee monitoring within the next five years.
Wikelski leads the Icarus Initiative (International Cooperation for Animal Research Using Space) based in Germany. Set to launch in 2015, Icarus aims to document animal movements, especially among smaller species, by utilizing an antenna on the International Space Station. The plan is to equip 5,000 to 10,000 animals with GPS tags that will transmit data back to the Icarus operations center.
Wikelski elaborates on the potential benefits of monitoring various species, including birds, bats, insects, and rodents, to gain insights into the spread of diseases such as malaria and avian flu. Once transmitters are small enough, he envisions tracking desert locusts to predict their plagues. Icarus will also explore the impact of climate change on animal migration patterns and the influence of invasive species on ecosystems. By identifying critical stopover locations for endangered species, the initiative could aid in conservation efforts.
Despite years of research, scientists remain uncertain about the causes of CCD. One prominent suspect is the Nosema virus, a fungal spore that thrives in the gut and leads to diarrhea, facilitating the virus's spread. Researchers are also scrutinizing a prevalent class of pesticides known as neonicotinoids. Studies from 2012, including one from the USDA’s Agricultural Research Service and another from the University of Florida, indicated that these nicotine-derived pesticides render honeybees more vulnerable to the Nosema virus and can modify their gene expression in the presence of Varroa mites, the primary contributor to honeybee mortality.
Section 1.2: The Importance of Foraging Patterns
Honeybees are generally easy to monitor as they typically forage within a couple of miles from their hive, returning to specific food sources, such as flower fields, to collect nectar and pollen until resources are depleted. One-third of the food we consume—ranging from beets and broccoli to apples and almonds—relies on the pollination services of the commercially raised honeybee, Apis mellifera.
In 2007 and 2008, an international team of Australian scientists utilized tiny RFID (radio-frequency identification) tags, which emit signals using short-distance radio waves and require no battery. These lightweight tags were attached to bees, and scanners were positioned at the hive entrance. Bees would send signals upon departing and returning, allowing researchers to track daily trips. One study highlighted that bees exposed to pesticides reduced their foraging activity and took longer to travel between the hive and food source. However, these RFID tags couldn't monitor bee movements in the field as the Icarus Initiative intends to do.
Chapter 2: Innovative Tracking Techniques
The second video titled "Bee hive tracking cards- a Canadian Beekeeper's Blog" illustrates how tracking techniques can enhance our understanding of bee behavior and health.
Section 2.1: Creative Tracking Solutions
Dr. Claire Kremen, a conservation biologist at the University of California, Berkeley, employs a novel method to track bees in the wild. She captures bees and coats them in luminescent fluorescent powder before releasing them into hedgerows. At night, Kremen and her team venture into the field equipped with UV glasses, searching for vibrant traces of dye on the flowers visited by the bees.
“It’s akin to searching for a needle in a haystack,” she remarks. “If we could tag them and discover their nesting sites, it would be monumental for our understanding of these creatures’ biology.”
Jeff Pettis, the head of the USDA’s Bee Research Lab in Beltsville, Maryland, acknowledges that utilizing transmitters for bee tracking could prove immensely beneficial. He notes that when a bee colony collapses, the bees instinctively fly away to die, avoiding infecting the remaining hive, which complicates postmortem analyses.
“If we could recover more deceased bees, we could compare viral loads between those that died away from the hive and those in nearby hives that seemed healthy,” Pettis explains. This information could reveal the origins of the problem.
Section 2.2: Addressing Skepticism in Bee Tracking
However, not everyone is convinced. Eric Mussen, an apiculturist at the University of California, Davis, expresses concern about the feasibility of tracking bees. With more than 1,000 eggs laid in a hive daily, he questions how researchers would select which bees to monitor. He warns that many scientists may encounter disappointment when finding transmitters attached to bees devoured by predators.
Mussen also raises concerns about establishing a link between pesticide exposure and bee behavior. If Farmer A cultivates a crop treated with a specific pesticide, but the bee forages in Farmer B’s adjacent field, isolating the source of contamination would be challenging. “To accurately trace pollen loads, researchers would need to continually capture the bees visiting Field A and analyze their pollen in a controlled manner,” he suggests.
Despite these hurdles, Wikelski remains optimistic. “Tagging just one bee and tracking its movements can yield invaluable insights,” he states. “Then, tagging another could provide even more information.” He believes that monitoring bees between agricultural fields is achievable, urging scientists to take action and refine their methodologies over time. “The most pressing questions may become irrelevant once sufficient data is gathered.”
While the Icarus Initiative contemplates tracking honeybees, the team awaits the development of a radio transmitter weighing no more than 20 percent of a honeybee’s body weight—around 24 mg, equivalent to the RFID tags used by Australian researchers. Creating a transmitter of such minimal weight, complete with a battery to emit radio waves, presents challenges but is feasible, as noted by Michel Maharbiz, an associate professor in Electrical Engineering and Computer Science at the University of California, Berkeley. “Currently, there’s a practical limit to battery size,” Maharbiz states. “However, the demand for compact telemetry transmitters is growing, driving companies to innovate smaller and more powerful chips.”
“We are merging nature with technology,” Wikelski asserts. “People have claimed we couldn’t track songbirds, yet we’ve succeeded. I am confident we will be able to protect honeybees; we just need to deepen our understanding of them.”
Julia Scott is an award-winning journalist and radio producer whose work has been published in Best American Science Writing. Her articles have appeared in the New York Times, Modern Farmer, and on Marketplace and the BBC World Service.