Contents:
- Introduction: Bees and Climate Change
- Climate Change Leading to Habitat Loss
- Climate Change Impact on Overwintering
- Premature Blooming Causing Mismatched Plant-Pollinator Timing
- Changing Floral Fragrances and Climate Change
- Pests and Pesticides
- Carbon Dioxide Changing Plant Chemistry
- Queen Bees, Infertility, and Climate Change
- Honey Production Decreasing Due To Climate Change
- Bees and Climate Change: Promising Research
- How We Can Help Bees in Our Changing Climate
- Honey Bees Guiding and Inspiring Action
- Best Bees Research and Beekeeping
Introduction: Bees and Climate Change
Over the past several decades, the world has begun observing increasingly unusual weather patterns due to climate change. Tropical storms, intense heat, flooding, drought, and forest fires have ravaged the globe, resulting in mass ecological devastation and displacement. Scientists from leading research organizations predict these weather extremes to become ever more common, leading us to wonder what other butterfly effects climate change has in store.
Enter pollinators, or specifically, the honey bee. Apis mellifera, better known as the honey bee, is one of many magnificent insect species which pollinate nearly 75% of all major food crops across the United States. Dating back over 33 million years old, with estimated over 20,000 different species, bees of all varieties have helped hold our ecosystem together since the dawn of civilization.
However, that peaceful coexistence between humans, plants, and pollinators is being challenged. Over the past 40 years, pollinator health – especially that of bees – has seen the largest decline in human history. From habitat loss, to mismatched plant-pollinator timing, to honey production, climate change has dangerous implications to the survival and success of our pollinator friends.
Climate Change Leading to Habitat Loss
Talking about climate change, the phrase “habitat loss” gets thrown around a lot. With erratic weather patterns, wildfires, rising sea levels, and higher temperatures, environments which were once suitable for various forms of life are beginning to change. On top of that, the global human population continues to increase, resulting in further demands for urban, suburban, and agricultural development. Our need for more land paired with shrinking resources has begun pushing native species from their natural habitats.
INCREASING TEMPERATURES AND HABITAT LOSS
Recent studies on native bees and habitable spaces have shown that changes in temperature have shrunk pollinator habitats, limiting migration zones for native bees. Having originated in colder climates, or evolving to live in them, some species of bees are unable to adjust to new warmer temperatures. As temperatures rise, these bees are forced to migrate to colder zones, shrinking their habitats, and limiting their ability to pollinate their familiar environments.
DROUGHTS AND FLOODS
Increased temperatures also pose dangers on bees’ access to drinking water. Like us, bees need water in order to survive; however, in environments where droughts are becoming ever more common, bees are struggling to meet their needs.
Not only do droughts limit bees’ access to water, but also pose a threat to plants, which also require water to bloom and produce nectar. The relationship between droughts, plants, and pollinators has been vigorously studied — findings show that, without enough water in an ecosystem, regular plant life is less likely to grow. Additionally, the plants that do sprout have a lower chance of producing nectar, meaning the ecosystem has decreased capacity to sustain pollinator life.
On the completely opposite end, too much water is equally devastating to the environment. As we witness harsher storms and rising sea levels, the occurrence of extreme flooding poses a risk to bees situated on coastlines or near bodies of water. If the area around a beehive were to flood, so would the bees’ nests and foraging areas. While there have been cases of bees surviving their hives being flooded out, over-waterlogged plants they forage on may not.. This creates a scarcity of resources within their already shrinking habitat.
In 2022, Hurricane Ian destroyed up to 400,000 beehives in Florida. Its high-speed winds and mass flooding also devastated the bloom of the Brazilian pepper tree, stripping the plants nearly bare. The plant is a significant source of nectar for Florida bees, and without it, they could not produce their normal fall honey crop. This launched a domino effect of poor honey production, with the bees’ state of malnutrition spilling over into the following year.
AGRICULTURAL INTENSIFICATION AND HUMAN DEVELOPMENT
Beyond acts of nature, human activity has also degraded or destroyed wild areas. The population of the human race is at an all time high, and as we grow, we are forced to migrate and take over natural spaces.
Agricultural intensification is the process of increasing agricultural productivity in order to produce more food for our growing populations. These practices often expand agricultural land, taking away pollinators’ habitable areas, and significantly decreases biodiversity as well as reduces habitat connectivity. This expansion often results in increased pesticide use, which has devastating effects on pollinator health.
The rapid spread of human development has led to habitat fragmentation, where larger ecosystems are pardoned off and sectioned into smaller slivers of an unaligned whole. This results in unharmonious sub-ecosystems that don’t always contain all the attributes necessary for a highly functioning ecosystem.
Domestication of natural habitats, such as lawn culture and curated parks, also work to the detriment of pollinators, as it destroys nesting habitat and important foraging resources. Additionally, domestication sometimes results in the introduction of invasive plant species. These non-native plants are able to outcompete native plants for already limited resources, impacting the abundance of native flora required by pollinators like bees to forage and reproduce.
Climate Change Impact on Overwintering
Unlike many insects who hibernate or die out in the winter, honey bees actually undergo an adaptation of hibernation referred to as ‘overwintering.’ Once temperatures drop below approximately 50°F (10°C), the bees cluster inside their hive in a massive huddle to preserve heat. Winter bees are born in late fall and have larger fat bodies which help them conserve heat, expend less energy, and limit food consumption. These bees live significantly longer than average honey bees, hibernating through the winter until early spring, where they act as the first generation of bees to provide resources for the colony.
FALSE SPRINGS EFFECT ON POPULATION GROWTH
With climate change causing warmer winters with strange flash freezes and unpredictable weather patterns, colonies have begun to preemptively exit their overwintering state. Awoken to a still harsh and barren world, forager bees fail to find the nectar and pollen stores they have been waiting for all winter. Then, as temperatures swing back into freezing, bees who have left the hive or cluster are left out to paralyze and freeze in the cold. These occurrences not only confuse the bees, but weaken the colony significantly, sometimes leading to starvation or entire colonies freezing.
Furthermore, early springs can mess with the queen’s brood laying. Brood, or bee babies, undergo four stages before becoming bees: egg, uncapped larvae, capped larvae, and pupa. Depending on what type of bee they will become, it can take between 15 to 24 days for an egg to develop into a bee, which means the queen needs to be laying constantly spring through fall for the colony to maintain typical population growth patterns.
Brood requires a lot of food and energy to develop fully, which means that the rest of the colony must be able to collect enough pollen and honey in order to provide for the new hatchlings. When temperatures reach above 50°F earlier than normal, it signals to the queen that it’s time for the new season. However, the flowers, grasses, and trees which the bees require for food are not always ready that early on. Without the resources to feed an increased population, this mismatch in timing could lead to colony starvation. Not only that, but temperatures swinging too low after brood production has begun can also freeze new eggs, killing them and creating more work for the weakened colony.
DETERIORATION OF COLONY AGE STRUCTURE
As our climate begins to shift, with summer and autumn lengthening, bees are no longer forced into hibernation as early as in decades past. Instead, due to the heat, bees are able to prolong foraging much later into the season. While this may initially read as a positive, this situation results in something referred to as ‘skewed colony age structure.’
Colony age structure is an inherent property of honey bees which helps determine the division of labor and define how age-related events, like disease and death, affect the colony’s overall health. For example, a typical honey bee will live up to six weeks. In that time it will cycle through every job within the hive in a set order: nursing first, then capping cells, attending the queen, guarding the hive, and finally foraging. When the autumn season is prolonged, it allows bees which were previously not able to mature into the foraging stage to exhaust themselves prematurely.
Ideally, the queen will go into the winter with a hive of younger, winter bees who are able to sustain themselves for the duration of the winter. However, the lengthening season results in larger-than-typical numbers of older bees overwintering, leading to a sudden die out of the older bees right at the beginning of spring. This phenomenon referred to as the ‘spring dwindle’ leads to a decreased colony size, which in turn affects the ability of the colony to gather necessary resources and be attended to properly in preparation of the spring season.
Premature Blooming Causing Mismatched Plant-Pollinator Timing
Shifts in seasonal timing have massive impacts on the many types of plants that pollinators rely on for nectar, pollen, and shelter. Premature blooming and mismatches in plant – pollinator timing may be the most dangerous effect of climate change on any given ecosystem as a whole.
As some plants begin to sense warmer temperatures, they send signals to their roots to begin drawing up the water they will need for blossoming. However, since spring temperatures have become more erratic — with earlier warm days followed by sudden deep freezes — many plants that have prematurely started their spring preparations can be killed or severely weakened with these sudden changes. As more plants struggle to bloom, the already limited resources for colonies can lead to starvation, dwindling populations, or less honey production later in the season.
These effects often result in a cycle of destruction within an ecosystem where pollinators that cannot find sustenance die out, and the plants that depend on them for pollination struggle to reproduce. In short, less pollinators means suboptimal or no pollination. This can be particularly problematic in mountain and desert areas, where the spring blooming season can be relatively short. Without their usual army of pollinators, plants which are unable to be pollinated may be under threat of extinction, in turn leading to less biodiversity and fewer resources for the bees the following season.
Changing Floral Fragrances and Climate Change
Even more concerningly, new research has shown that increases or inconsistencies from usual seasonal temperatures have led to some plants releasing slightly different floral fragrances. One study on ozone pollution and floral odors discovered that stress from extreme heat caused certain flowering plants to emit defensive odors. Since bees rely on familiar scents to locate flowers, this poses an issue, as by releasing defensive odors, it changes the plants’ typical scent profile, thus making it more challenging for bees and other pollinators to locate them.
Additionally, bees’ ability to detect scents is being impaired by climate change and air pollutants, as air pollution works to mask floral fragrances, making it more difficult for them to find the flowers they need. Ozone has been shown that it has the ability to both decrease colony health and greatly reduce bees’ ability to locate food sources. A study published in 2022 showed that, after exposure to diesel exhaust and ozone, the number of flowers each bee visited dropped by nearly 90%.
While both of these developments may have different causes, they boil down to the fact that climate change is disrupting pollinators’ ability to detect familiar scents. As plants change their scents due to warming temperatures, bees and pollinators are no longer able to find them. Then, as air pollution worsens, it deteriorates pollinators’ already challenged ability to smell. Without one of the major senses they use to locate their food, pollinators become incredibly limited in their food supplies and diversity of pollen. This disturbance also poses an implication on those plants in need of pollination, since if they cannot be found, they will not reproduce, further emphasizing the importance of the relationship between pollinators and plants.
No pollination = no plant reproduction.
Pests and Pesticides
When plants are sick or weak, pests can tell and will flock to the vulnerable plant. As growing seasons shift and plants struggle to adapt to changes in seasonal timing, pests will take advantage of the increasing proportion of vulnerable plants, resulting in greater pesticide use.
Pesticide exposure has always posed a massive risk to bees. Countless studies have shown that pesticide exposure also causes an impairment in immune functioning, birth defects, and can degrade cognitive functioning in areas such as memory and behavioral learning. These vulnerabilities have the ability to weaken significantly to a place where they can easily be wiped out from population loss or increases in pest activity and disease.
While climate change causes dangerous stress on bee populations, the opposite occurs for the number one predator of honey bee colonies. Varroa mites, indigenous to Asia, are an invasive species of parasitic mites that attach themselves to the bodies of adult bees to feed on their fat body tissue. This weakens the bees’ immune systems, leaving them vulnerable to the number of viruses the varroa spread.
Varroa mites reproduce in honey bee brood, invading uncapped larvae, and laying eggs. When those eggs hatch, they feed themselves on developing larvae, eventually growing into adult mites that can latch onto matured bees. During seasons like late fall and winter, where it is too cold for the queen to lay, varroa tend to die out. However, with warmer autumns, the queen can continue laying right up until winter starts, meaning lots of brood for varroa to multiply from.
Warmer falls have allowed varroa mite season to last longer into the fall, challenging the strength of the hive as they prepare for the winter season. As colonies enter the winter with skewed colony age structures, high mite populations, and sickness, they stand very slim chances of being able to keep up with all their troubles.
Not only are varroa mites a risk, but small hive beetles (SHB) have also seen positive growth as the climate warms. Similar to varroa, small hive beetles are parasites which feed on any resources they can find, reproducing in the honey, pollen, or brood stores of a colony. While not as invasive as mites, these beetles can still pose a significant strain on a colony by taking away precious resources.
Development time is a limiting factor for SHB success. In the case of shorter seasons and colder temperatures, larvae can sometimes fail to complete the metamorphosis cycle. However, under warmer climatic conditions, pupal survival rates are increased, meaning more beetles which are able to reach maturity and lay future generations. The length and heat of a season acts as a predictor for the success rate of SHB populations, and with longer, warmer autumns each year, we are able to see that success at the detriment of honey bee colonies.
Carbon Dioxide Changing Plant Chemistry
Rising CO2 levels are not only warming our planet, but also changing the chemistry of our plants! A study done by USDA Agricultural Research on CO2 and pollen interactions found that increased CO2 levels have resulted in decreased protein content in pollen across varying plant species.
This discovery poses a real threat to the survival of many wild pollinators, as well as honey bees, who depend heavily on pollen for the fats, proteins, minerals, and vitamins they receive through consuming it. As pollen concentration decreases, bees’ ability to sustain themselves on naturally found pollen also decreases. Without the right nutrients needed for development, bees may begin to limit their brood rearing, thus shrinking their population. Pollen also greatly affects the weight and success of larvae, meaning that with less effective pollen, we can expect to see weaker, underdeveloped bees.
Many commercial beekeepers have already observed this issue and begun providing supplemental feed or pollen patties to their colonies in the early spring and fall in an attempt to boost the strength and size of brood populations. However, not only is supplemental pollen expensive, overly processed, and not as nutritionally beneficial, but it also isn’t available to wild bees and other pollinators.
Queen Bees, Infertility, and Climate Change
Being the only bee who can create new workers, the queen bee is imperative in maintaining colony success and structure. Her genetics, laying pattern, health, and age all play into how well a hive is able to function — however, not even the queen is immune to the effects of climate change.
As temperatures continue to rise, especially in regions which are historically more temperate, queen bees become increasingly at risk of laying fewer fertile eggs. Researchers from the University of British Columbia discovered that exposure to higher levels of heat caused queens to produce proteins that killed sperm, significantly reducing their ability to lay fertile eggs. This then creates a domino effect where, if the queen doesn’t lay fertile eggs, the colony has fewer workers, and if the colony has fewer workers, there are fewer bees to collect resources for the queen. With fewer resources for the queen, the fewer eggs she is able to lay, and so on.
As we know, higher temperatures are one of the most common things associated with climate change. Nearly every climate in the world is becoming slightly warmer, meaning that this discovery has the potential to affect possibly every bee species on the planet.
Honey Production Decreasing Due To Climate Change
Taking all of these factors into consideration, it is evident that honey bees are under more stress than ever before. It is sometimes difficult to accurately assess how these circumstances are affecting a given species. However, because of extensive research on honey bees and increased farming, we are able to see how beekeeping has changed over time and measure those changes in a very tangible way — through honey production.
Since 1976, the USDA has been collecting data from farmers on honey production (among other things) and have released annual Honey Reports, which are available to the public. Through these reports and findings, we are able to see that, compared to past decades, honey production and colony health have significantly worsened in recent years.
Reports released by the USDA shows a relatively consistent downward trend from the late eighties to now, supporting the notion that, despite the growth within commercial beekeeping, other environmental and anthropogenic factors have resulted in decreased honey production.
Bees and Climate Change: Promising Research
So, what do we do with all this information? Well, luckily many researchers across the world, including researchers at The Best Bees Company and our affiliated nonprofit, The Urban Bee Lab, are incredibly passionate about finding ways to navigate these developing dilemmas and uncover possible solutions.
HONEYDNA & HABITAT RESTORATION
HoneyDNA is a unique science developed through Best Bees and our partners which uses advanced genomic sequencing to reveal the identity and percentage of floral sources bees foraged from on any given sample of honey. HoneyDNA offers significant insight into the unique makeup of honey bee environments, allowing us to know exactly what plants a given colony is foraging from, and the significance of those plants in context of the entire ecosystem.
Over the past several decades, wildfires have dominated the newstream for decimating forests and wreaking havoc on people, animals, and their homes. These forms of natural disasters require immediate attention in order to rehabilitate the affected habitat and rework it into a livable space. The data from HoneyDNA is like striking gold when it comes to rebuilding after natural disasters, as it serves as a blueprint for what plants were previously necessary for that ecosystem to flourish.
HoneyDNA also has the ability to alert us to harmful or invasive plant species that may be lurking in an area. Non-native plants or invasive species often work to disrupt natural botanical life, resulting in suboptimal biodiversity levels, which can harm the functioning of affected ecosystems. Taking time to prioritize restoring biodiverse and healthy ecosystems, either after wildfires or otherwise, may actually improve the original ecosystem and make it stronger than before.
Our non-profit partner, The Urban Bee Lab, has worked with Best Bees and our data to create a unique map highlighting HoneyDNA from around the world. If you are more curious about the makeup of your local plants, you might be interested in learning more about their mission or getting your own HoneyDNA from home.
MICROALGAE AS A NUTRIENT SUBSTITUTE FOR BEES
Recent research revolving around the various causes and effects of climate change has brought researchers to begin experimenting and questioning the properties of a creature which has existed since the beginning of organic life: microalgae. Studies in Australia have shown that microalgae in cow’s diets has the positive effect of being both nutritious and effective at considerably lowering CO2 emissions.
This newfound interest in the varying positive effects of these protists – or single celled organisms like algae – led entomologists Vincent Ricigliano and Michael Simone-Finstrom to experiment with the possibilities of microalgae as a supplement to bee diets. Their research determined that Arthrospira platensis, or spirulina, appears to be a parallel pollen substitute for bees in terms of nutrition and offers bees the necessary 12 amino acids they cannot produce themselves. It even has improved probiotic properties that have been shown to advance bee gut health.
Improvement of gut health is an increasingly important issue for beekeepers, as studies have shown that warmer temperatures are changing honey bee gut microbiome. Like most animals, bees require consistent thermoregulation of their bodies in order to function properly. However, studies have shown that exposure to excessive heat can have negative effects on important stomach bacteria growing in the gut microbiome. It is possible that spirulina may be able to help boost the strength of bees’ gut systems and help them maintain a consistent microbial balance, even under new heat stress.
Furthermore, the discovery of spirulina as a substitute for pollen is exciting for beekeepers looking for a less processed pollen substitute. While some beekeepers do make their pollen patties at home, many prefer pre-manufactured patties consisting of a dry base protein derived from soy, wheat, egg, yeast, or lentils. These patties, while effective, require more time, energy, water, and crops to produce compared to spirulina.
Spirulina powder is already an established diet supplement for humans, so it’s incredibly easy to access and costs less than it would to purchase all the materials to make a pollen patty at home. To feed a hive with spirulina, one must simply mix it half and half with sugar water and leave it out for the bees to consume. This process is not only cheaper, but easier for beekeepers, especially hobbyists, to supplement their bee’s diets with.
How We Can Help Bees in Our Changing Climate
Now more than ever, it is easier to make positive changes for the pollinators in the ecosystems you share!
PLANTING POLLINATOR GARDENS
The easiest way for people to help bring bees into their neighborhood and provide them with an abundance of resources is by planting pollinator-friendly gardens. Planting gardens not only adds a burst of color and nature into your yard, but also acts as a food source for the many pollinators who visit it. If you’re looking for some specific plants to attract honey bees to your garden, there are many blogs on our website that would be happy to point you in the right direction. Starting with six awesome plant types that will attract bees to your garden.
Before jumping right in, it is important to research the native plants in your area to make sure that you are not introducing an invasive species or plant which cannot be pollinated by bees into your neighborhood. Using native and pollinator-friendly non-native plants instead of invasive species boosts your natural ecosystem instead of possibly compromising it. There are organizations in every state, and sometimes region, dedicated to comprising lists of plants native to their zones. The US Horticultural society has a list with these specific state organizations which will point you in the right direction.
Obviously, not everyone has their own lawn or garden space, but that doesn’t mean there’s no other option. If you don’t have space at your home, or you live in an apartment, you can check out the local community gardens in your area to sign up for your own zone. These community gardens are often free spaces where people are able to come together and learn more about gardening with the people in their very own neighborhood!
USING LESS PESTICIDES AND EMBRACING WILDNESS
Did you know that your grass lawn is one of 40 million acres – 2% of all land in the US? This makes grass the single largest irrigated crop we grow (more than corn, wheat, and fruit orchards combined). The dominance of manicured grass lawns started with the rise of suburbia in post-World War 2 America. The perfect lawn became a symbol of the American dream; a lawn expressed the national ideal that, through hard work, home ownership and a patch of green could be within reach for every American.
The ideal lawn must be watered, mowed, repaired, and cultivated. It requires a great deal of effort, but luckily for homeowners, the chemicals that had been researched during the war for bombs and weapons turned out to be multi-purpose; they could also be used for fertilizers and pesticides.
Every year, American homeowners use approximately 80 million pounds of pesticides to maintain their lawns. This is one of the factors contributing to pollinator decline — pesticides not only remove floral resources, but also impair pollinators’ immune response, learning capabilities, foraging and navigation abilities, and reproductive processes. And these are just the effects when exposure to pesticides doesn’t just kill pollinators outright.
As we strive to aim toward a more sustainable and healthy world, it becomes necessary to reassess where we funnel our energy for our outdoor spaces. Perhaps instead of subscribing to an outdated ideal of lawn culture, it is now time to try embracing a more nuanced one. Take a step back from trying to reshape and curate nature from something it isn’t, and let it run a little wild!
No Mow May is a movement started to bolster pollinators in the beginning of the spring when many insects are first beginning to emerge. By not mowing your yard, you allow all sorts of natural and native plants to bloom, allowing your local pollinators to gather their much needed resources closer to home.
If a whole month is too much for you, simply waiting a week or longer than you might typically mow can help new bees gather the resources they need. When regarding this issue, it is so important to remind yourself that even small change has an impact.
SUPPORTING LOCAL BEEKEEPERS
You can support the bees in your area by supporting your local beekeepers. They’re the ones making sure that the bees stay alive and healthy so they can pollinate local agriculture, bolster the biodiversity of your neighborhood, and contribute to your local ecosystem’s health.
By supporting local beekeepers through buying honey, candles, or whatever else, you help them to continue expanding, building, and healing the bees pollinating your backyard.
Besides, buying local honey is ultimately better for your body and your community. Buying local goods, rather than importing them, is a small way of reducing your carbon footprint and putting money back into the economy which directly surrounds you. By buying locally, you are supporting your neighbors who often depend on local sales for their livelihoods.
And if that wasn’t enticing enough, did you know that honey actually has many positive health benefits? For thousands of years, humans have been using honey for a multitude of health benefiting reasons. From antibacterial properties to mummification, the multi-use capabilities of honey are widely documented and tested.
Honey Bees Guiding and Inspiring Change
Ultimately, honey bees are a fantastic indicator species whose successes, as well as failures, can tell us a ton about how their ecosystem is doing as a whole. Looking at these creatures through the lens of climate change helps us to understand where we need to be putting efforts in order to see a positive turn around.
Climate change is an increasingly urgent issue that often feels too massive for people to have power over. The implications of its impact on our pollinators could prove to be devastating to not only our global food system, but our planet as a whole. However, we can not afford to let the scope of the issue overwhelm us. Instead, we must take action.
No matter how big or small, your choices on this planet make an impact on your environment. So even if you’re not ready to keep bees, maybe you should take a page out of their book. We’re all part of something bigger than ourselves, trying to find ways to work together for the better of the whole.
Best Bees Research and Beekeeping
The Best Bees Company is a Boston based beekeeping organization whose mission is to collect data about honey bees while promoting and protecting pollinator health. Working out of over 20 cities across the US, we install corporate and residential hives on client properties, with each location providing data points which connect a national network of data-yielding beehives.
The data collected by Best Bees have been used by institutions such as NASA, MIT, Harvard, and National Geographic to further pollinator research and provide context for countless beekeeping ventures nationwide.
If you are curious about adopting a hive at your home or business, you can get connected here and we would be happy to provide you with further information about what that would look like.
