Did the Bees Need Eclipse Glasses too?
Dr. Ferhat Ozturk, Assistant Professor of Practice in Integrated Biology at the University of Texas at San Antonio (UTSA).
On April 8th, 2024, Americans across the country spread their picnic blankets and adorned special safety glasses in anticipation. This particular eclipse was a total solar eclipse, visible along a narrow path known as the "path of totality," stretching from Mexico to Canada, traversing states from Texas to Maine. A solar eclipse occurs when the moon positions itself between the Earth and the sun, casting its shadow upon the Earth. Conversely, lunar eclipses happen when the Earth interposes between the sun and the moon, projecting its shadow upon the lunar surface (these are visible to people on the entire night side of the Earth when the eclipse occurs).
While the relatively narrow strip of land in the continental US was fortunate enough to witness a total eclipse on April 8th, it's worth noting that 99% of us in the lower 48 only experienced a partial eclipse. If you're longing for the total experience, you have plenty of time to plan ahead – the next total solar eclipse won't grace our skies until 2044!
Curious how this celestial spectacle connects to bees? Enter Dr. Ferhat Ozturk, Assistant Professor of Practice in Integrated Biology at the University of Texas at San Antonio (UTSA). With a deep passion for learning, researching, and educating in the realm of biological sciences, Dr. Ozturk has dedicated twelve years to the study of honey and honey bee research. At the time of my video chat with Dr. Ozturk, he and his students were busy analyzing data from the April 8th eclipse. Before delving into the captivating intersection of bees and eclipses, I was keen to learn more about his journey into the world of honey bees and his other areas of research interest.
During his post-doctoral studies, Dr. Ozturk dedicated his research efforts to exploring cleft palates. Armed with this specialized knowledge, he later transitioned his focus to cancer and wound healing, drawing connections to the biological pathways associated with cleft palate formation during fetal development. It was during this journey that he developed a keen interest in the historical use of honey for wound healing—a practice that traces back to ancient Egypt. Dr. Ozturk acknowledges that the widespread adoption of antibiotics led to a decline in the use of honey as a healing agent. However, since the 1990s, scientific interest in honey's medicinal properties has experienced a resurgence.
Today, Dr. Ozturk has gained recognition for his sophomore biology research initiative course at UTSA titled "Medicinal Properties of Honey." This course stands out as one of UTSA's Course-Based Undergraduate Research (CURE) offerings, providing students with a hands-on research experience. What sets this yearlong course apart is its emphasis on exploring the research process (where outcomes are unknown and unplanned), which is a departure from traditional laboratory-based undergraduate courses. This course is part of the HONEY (Honeybee Oriented NextGen Entrepreneurs and Youth) Pathway Program, generously supported by a $2.8 million grant from the U.S. Department of Agriculture's National Institute of Food and Agriculture. This UTSA CURE course is designed to inspire the next generation of beekeepers and bee researchers, and Dr. Ozturk is enthusiastic about providing students with opportunities that will benefit them in their post-graduation pursuits.
Antibacterial Properties of Honey
The semester begins with introducing students to honey bees and beekeeping practices through workshops and interactions with local beekeepers. Following these immersive encounters, students dive into the planning and execution of research projects, aiming to uncover the antioxidant and antimicrobial potential of locally sourced honeys. As a recent graduate with a degree in chemistry, I was personally enthralled by Dr. Ferhat's deep dive into the investigation of honey's antibacterial potential.
Honey boasts a multitude of properties that contribute to its remarkable antibacterial prowess, with different varieties often harboring unique combinations of microbial-fighting prowess. Primarily, honey's acidic nature (typically within a pH range of 3.0 to 5.0) sets the stage for its antibacterial action. While most bacteria thrive in a neutral pH range of 6.5 to 7.5, honey's acidity creates an environment inhospitable to bacterial growth. This acidic environment is largely attributed to the presence of organic acids (gluconic, citric, malic, and oxalic) within honey's composition.
A fun chemistry tidbit: How do these organic acids make the environment too acidic for bacteria?
When honey is applied to a wound, bacteria within the wound find themselves immersed in an excessively acidic environment. Consequently, the bacterial cell membrane is in a state of disequilibrium, prompting the organic acids present in honey to cross the membrane in an attempt to restore balance. This influx of acids disrupts the internal pH balance of the bacterial cell, rendering it excessively acidic and ultimately untenable for survival.
A general visual representation of the equilibrium process. The hexagons represent organic acids present in honey. Over time, the acids are equilibrated across the bacteria cell membrane.
Another key aspect contributing to honey's antibacterial properties lies in its enzymatic content. Enzymes, essentially proteins that accelerate chemical reactions, play a pivotal role in honey's ability to produce hydrogen peroxide. While conventional wisdom may have once advocated for the application of hydrogen peroxide and alcohol to wounds—a practice now discouraged due to their potential to cause tissue damage—honey offers a gentler alternative. In controlled "honey doses," the production of hydrogen peroxide serves as an effective antimicrobial agent, aiding in the wound healing process without the risk of tissue damage associated with direct chemical application.
Honey's high sugar content is yet another mechanism behind its potent antibacterial properties. With its elevated sugar-to-water ratio, honey is considered to be a hypertonic solution. Consequently, when applied to a wound, honey creates an environment where water is drawn out of bacterial cells via osmosis—a similar process that occurs in the opposite direction as the equilibrium of organic acids described earlier. As water exits the bacterial cells, they undergo dehydration and shrinkage, rendering them unable to survive.
“Honey doesn’t attack bacteria in one way, it has a synergistic affect; it is a multifaceted armor against bacterial infections.”
While I've only touched upon three antibacterial attributes of honey, its repertoire of healing properties extends far deeper. Introducing a novel, albeit ancient, bacterial treatment like honey could prove indispensable for humans, particularly as bacterial infections grow increasingly resistant to antibiotics. Honey's efficacy in combating infections mirrors its longstanding role in supporting the health of bees, whom rely on it to fend off their own ailments. Remarkably, bacteria have yet to overcome honey's antibacterial effects, which only reinforces its enduring abilities as a natural healer.
Pioneering Research on Honey Bees and Eclipses
Shifting our focus back to the main topic, I asked Dr. Ozturk how he transitioned from studying honey to investigating honey bee behavior during eclipses. He explained that within the HONEY program at UTSA, there was a concerted effort to support professors from various departments. Both Dr. Angela Speck, Professor and Department Chair of Physics and Astronomy, and Dr. Mariah Hopkins, Professor and Assistant Department Chair of Integrative Biology, expressed keen interest in working with Dr. Ozturk. This interdisciplinary collaboration merged expertise in honey bees, behavioral biology, and eclipses. Before delving into their research, I wanted to provide background on foundational concepts.
How do bees “see”?
Honey bees rely on polarized light from the sun to navigate distances of 3-5 miles from their hive to forage for food sources. The Rayleigh Sky Model describes the phenomenon of Rayleigh Scattering, wherein light is scattered by air molecules, water, dust, and other aerosols, thereby creating distinct polarization patterns in the sky. To the honey bee eye, these patterns manifest as a band that dynamically shifts with the movement of the sun throughout the day. Remarkably, this serves as their built-in GPS and allows them to pinpoint the precise location of their hive. As beekeepers, we frequently witness "orientation flights" when introducing hives to new locations. As we uncover the hive entrance, worker bees engage in circular patterns of flight around their hive, effectively encoding the coordinates of their new location.
A simplified version of a polarization pattern to illustrate the band of color seen by honey bees. In a more polluted area, the polarization pattern might appear different to a honey bee eye than in a more rural area.
Eclipse types: Understanding the variations
Solar eclipses come in three varieties: total, partial, and annular. As described earlier, a total solar eclipse occurs when the moon aligns perfectly with the sun, completely blocking its light for a brief period. Conversely, a partial solar eclipse takes place when the alignment between the Moon and Earth is not precise, resulting in a crescent-shaped sun. An annular solar eclipse happens when the moon obscures the sun near its farthest point from Earth, leaving a ring of sunlight visible around its edges. When total or annular solar eclipses occur, individuals outside the path of totality witness a partial solar eclipse. While honey bees are mainly affected by total eclipses due to the complete loss of polarized light, it's worth noting that other types of eclipses don't go unnoticed by them.
The three common solar eclipse types.
While many animals have been observed during eclipses, there is a lack of published data on honey bee behavior during these celestial events. Dr. Ozturk elaborated on previous research efforts during the 2017 total eclipse, which followed a thinner path of totality spanning in a near-opposite diagonal pattern to the 2024 eclipse.
With commendable efforts from The University of Missouri, volunteers, and elementary students across the country, researchers monitored bee activity (not just honey bees!) during the 2017 eclipse at 16 flower locations. Their findings revealed a fascinating phenomenon: while bee activity remained robust throughout the day and during the partial eclipse phases, it abruptly ceased during the few minutes of the total eclipse. During this brief period of complete darkness, bees at the monitored flowers appeared to land and settle, resembling nighttime behavior as they seemingly drifted off to sleep right on the flower petals. However, as soon as the sun began to emerge, bee activity swiftly resumed, returning to normal as though nothing out of the ordinary had occurred.
Dr. Ozturk's research was conducted using three hives at UTSA and three additional hives in Uvalde, Texas, generously donated by a student for the studies. The first event they documented was the annular eclipse on October 13th, 2023. This eclipse held significance as its path intersected with that of the total eclipse on April 8th, 2024, forming an X with San Antonio coincidentally positioned at the center. It served as an excellent opportunity to refine the data collection process, acting almost as a rehearsal for the upcoming total eclipse.
Dr. Ozturk and his team of research students employed both audio and visual recordings to gather data. Acoustic devices were utilized to capture the buzz of bees within the hives, while video recordings monitored hive entrances and exits. Throughout both events, all six hives remained in their exact locations. Additionally, data was collected on days preceding and following the eclipses, as well as during various weather conditions (cloudy versus sunny days), to establish baseline levels of bee activity and foraging behavior under different circumstances.
Dr. Ozturk and UTSA students in their beekeeping gear! Photo generously shared by John Elizondo, Public Affairs Specialist III in the UTSA Office of University Strategic Communications.
Walter Kaiser's 1983 discovery revealed that honey bees exhibit sleep patterns similar to those of humans, with periods of rest lasting between 5 to 8 hours within a 24-hour cycle. These sleep periods often manifest as short naps, occurring intermittently during foraging activities and becoming more prolonged during nighttime hours within the hive. Notably, the orientation of a hive can significantly influence colony health, with southeast-facing hives prompting bees to emerge and forage earlier than those facing other directions.
During both eclipses, there was a noticeable uptick in activity levels at the hive entrances approximately 10-15 minutes prior to totality. This surge in activity suggests that foraging honey bees detected the dramatic shift in polarized light as the sun transitioned from uncovered to partially covered. Sensing the impending darkness akin to nightfall, they hastened their return to the hive before losing all polarized light cues. Once back at the hive, there was a distinct reduction in bee movement and buzzing. Dr. Ozturk recalls noticing returning foragers crouching near hive entrances, seemingly on the verge of sleep or unable to locate the entrance before the sun was obscured.
Following the reappearance of the sun during the April 8th eclipse, an intriguing observation emerged: one of the three hives Dr. Ozturk was watching exhibited a delay in resuming foraging activity, remaining stalled for ten to twelve minutes. In contrast, the other two hives resumed their normal activity within five minutes of the sun's return. Dr. Ozturk plans to delve deeper into whether the orientation of a hive influences its response to eclipses or if the delayed hive simply lacked the robustness of the others.
While data analysis and publication for the April 8th eclipse is still underway, Dr. Ozturk's initial findings suggest a more pronounced response from the honey bees during the total eclipse compared to the annular eclipse. This disparity can be attributed to the presence of a thin circle of sunlight during the annular eclipse, which bees could potentially utilize for their polarized navigation system, and the lack thereof during the total eclipse.
The primary challenge facing this research is the scarcity of total solar eclipses visible in American skies, with the next occurrence not anticipated until 2044. Not only is it decades away, San Antonio will not even fall within the path of totality for this event! To address this obstacle, Dr. Ozturk aims to expand collaborations with other researchers, potentially enabling access to upcoming eclipse events in other parts of the world. By doing so, he hopes to advance our understanding of honey bee behavior during these celestial phenomena.
A heartfelt thank you to Dr. Ozturk for graciously joining this interview, and to John Elizondo for coordinating our meeting. I truly appreciated the opportunity to learn and delve into the fascinating world of honey bee research!
Please check out these UTSA Instagram accounts!
UTSA student-led honey bee club: @thehoneycombconnection
UTSA HONEY Pathway: @utsa_honeypathway