Why are domesticated honeybees dying?
Recently, I was working at a trade show in Secaucus NJ. Without exaggeration, I would say that one in every three people I spoke with asked me about honeybee populations. It is likely that you have heard that honeybee populations are declining and you probably have heard some of the many reasons behind the decline of once robust populations. It is also likely that you have heard that humans are at least partly responsible for the decline of honeybee populations. But, what these wonderful conversations in New Jersey inspired me to examine was the differences in population decline between wild, feral, and domesticated honeybee populations.
I guess the best place to begin would be defining the differences between wild, feral, and domesticated honeybees. Let's work backward beginning with domesticated populations.
Domesticated Honeybees - For ages, humans have domesticated animals and plants. Often, the aim of domestication is to produce or enhance desired traits. Consider the domestication of a particular canine breed. A professional breeder will select mating individuals based on the specific traits or attributes he or she would like to see in the offspring generation. It may be a difficult comparison, but humans have been breeding and managing honeybee populations in much the same way for centuries. However, rather than specific physical characteristics, domestic honeybee management often focuses on productivity or in the case of queen breeding, reproductive potential. Nonetheless, this selective breeding definitely qualifies as domestication.
Feral Honeybees - The Savannah Bee production facility is located on Wilmington Island just east of Savannah. For years folks on this island have been feeding a large population of feral cats. The recent ancestors of these animals were domesticated but at some point became stray and left to fend for themselves. As these stray cats bred, giving rise to next generations, they have become partially wild or feral.
When a honeybee colony swarms, the swarming population is often impossible to retrieve. As a result, this population ends up creating a wild hive in a natural space like a hollow tree. As the queen mates with wild-type drones and successive generations reside in natural, unmanaged hives the gene pool (collective genetic make-up of the colony) will expand and shift. The result is a honeybee that is not quite domesticated, but also not quite wild. This honeybee would be considered feral.
A wild hive fixed to a tree limb.
Wild Honeybees - Wild honeybees are of course bees that live in wild and native habitats. These populations have not been bred or engineered by humans. They have never been domesticated or lived in a managed hive environment. They are also the most difficult populations for scientists to monitor and understand.
Scientists believe that there are well over 400 unnamed bee species in North America in addition to the over 1000 named species. Many of these species are "shy" and really hard to find. Many of these species make their homes in remote areas. There are no data supported population numbers for wild honeybee populations.
The Decline of Honeybee Populations
All scientist agree that a complete loss of pollinators would certainly lead to the collapse of entire ecological communities. Pollinating species are considered keystone species, meaning that other species rely on them and their removal would ripple across the community. However, there is no clear scientific opinion about the decline of honeybee populations globally. Although domesticated honeybee populations are very easy to monitor, it is nearly impossible to estimate feral and wild populations.
Cross country trucking can be very stressful!
What do we know and why do we hear so much about the decline of honeybee populations? Most of the news we hear about Colony Collapse Disorder is focused on domesticated honeybees. In America, we have turned pollination into big business. Honeybees are routinely trucked across the country to service the pollination needs of large agricultural operations. Beekeepers move their hives from Florida to California to pollinate almond trees and then back to Florida to work the orange groves. In many cases, this service is a beekeeper's primary source of income which has outpaced income from honey and honeycomb sales.
The practice of transporting bees for pollination service is stressful in a few different ways for the honeybees involved. The actual road trip is difficult for honeybee colonies. The beehives are actually stacked on tractor-trailer rigs and moved across the country on the interstate system. Once they arrive in their new location, the bees have to acclimate to the conditions of the new environment. In addition, the bees are exposed to a whole new set of environmental contaminants such as pesticides, airborne pollutants, and soil contaminants like heavy metals.
Honeybees are commonly used for crop pollination.
Honeybees will arrive in California from all over the United States. As a result, the bees are in contact with many more colonies than they would be in a single apiary. This increased exposure rapidly increased the transfer of diseases and parasites. As the bees are moved back to their local environment they bring these diseases and parasites along. Regional parasites can rapidly move into new areas and spread through the local colonies.
We also know that the increased use of certain pesticides, in particular, neonicotinoids can be very harmful to honeybees and other invertebrates. It's not just the increased use of pesticides and fungicides, a wide variety of environmental contaminants can be found in almost every region. Even shifting climate patterns can introduce new stress to honeybee populations.
These stress factors combined can lead to increased attrition or mortality of domesticated honeybee populations. However, wild populations are not affected by any of these stress factors.
Wild honeybee populations have their own stress factors. Wild honeybees must contend with changing climate patterns and rapid loss of habitat and food sources. As climate patterns shift, the range of flowering plants can also shift. In addition, the annual timing of the bloom cycle may also shift. As a result, the honey bees must adapt to these dynamic environmental qualities. Such pattern shifts can cause stress for wild colonies but certainly not comparable to the stress factors domesticated hives are facing.
So, if we think of the wild-type bees experiencing low stress and the domesticated bees experiencing high stress, the feral bees probably fall somewhere in-between. The diseases and parasites that domesticated honeybees are exposed to during their cross country pollination adventures can be spread to feral populations through interaction with domesticated colonies.
Beekeepers must plan for a 30% colony die-off each year.
If we consider this stress spectrum, one would guess that mortality would be highest in domesticated colonies and lowest in wild honeybees. To a certain extent, this is true. We certainly do see high rates of mortality in domesticated honeybees. In fact, beekeepers plan for at least a 30% die-off each year. So, in order to properly estimate honey yield, beekeepers must raise and take care of 30% more colonies that they actually need to achieve their production goals. This practice increases operating costs for the beekeeper which ultimately drives up the price of honey.
The wild honeybee population mortality is much more difficult to estimate. Wild honeybees are somewhat reclusive. In addition, wild or native bees are difficult to identify. There are about 1000 species of wild bees in North America and an addition 400 or so that have not been named. Scientists speculate that there are at least 10% more that have never even been identified. These wild honeybees are also very hard to count. Although crude, setting bait traps for bees is really the best way to determine what species are present in an area. This type of capture does not deliver any population data, only an incomplete view or subset of the species living in the area.
Most scientists studying native honeybee populations hypothesize that wild populations are not decreasing at the rate of domesticated populations. The primary factor limiting the success of wild honeybees is the loss of habitat and food sources. As we continue to develop wild lands and convert them to stores and neighborhoods, the range for honeybees shrinks. Most often, grass replaces wildflowers and non-native species are introduced into landscaping.
As you can see, the question about honeybee populations is not a simple one. Sometimes people want to know if humans are responsible for decreasing honeybee populations. This answer is also not a simple one. I believe that humans are responsible for increased mortality of managed or domesticated honeybee populations. These colonies experience very high levels of stress largely at the hands of their beekeepers. Direct human involvement in wild honeybee populations is very limited. Indirect human involvement like exposure to insecticides, development of wild lands, and connection to climate change may be affecting wild populations. The problem with this statement is one of measurability. We simply do not have reliable wild honeybee population numbers. We do know that any loss of pollinators will ripple across an ecosystem and that we should do whatever we can to protect these noble insects.
Submitted By: Brantley Crowder