Honeybees have adapted to moderate climates over most of planet earth, and have done very well in the past at maintaining balance and surviving on their own for thousands of years. However with climate change, the advent of newer chemical pesticides, fertilizers, invasive parasites, disease and predatory insects... Honeybees are finding it increasingly difficult to survive, and the previous balance has been upset in recent years resulting in loss of bees at alarming rates! The decline of honeybees across the planet is cause for alarm, and a call for humans to act - AND DIFFERENTLY THAN WE'VE ALWAYS DONE IN THE PAST!
HYPO-HUMIDITY SYNDROME IN MASS-CRITICAL COLONIES
TEMPERATURE AND HUMIDITY CONSIDERATIONS FOR SURVIVAL
- Honeybees under normal healthy conditions, regulate and maintain their optimal internal hive temperature and humidity within some fairly tight tolerances. The HEAT and HUMIDITY requirements for rearing brood are different from those necessary for dormancy or colder winter periods.
- Observing and interpreting behaviors and methods under different environmental conditions is quite revealing to science. Observing critically small colonies has revealed behaviors to attempt control of Humidity and Temperature of a small egg patch on a frame, when it is not possible for the given colony size to control the entire box or immediate living space!
- Honeybees typically require a large population in a hive to gather the required nectar to store and prepare to survive cold months, and to maintain temperature and humidity. This adaptation of storing for winter and ramping population up in the spring and down in the fall, is the characteristic that allows the honeybee to venture into Northern colder climates and thrive. Temperature also affects the lifespan of the honeybee. During summer months, the lifespan is typically 6 - 8 weeks. However during cold months, dormant temperatures, internal to the hive, allow for increased longevity to 3 and 4 months! This is how a colony is able to survive winter months without rearing replacement brood.
- Honeybees use several mechanisms to maintain the desired temperatures and humidity levels. First, the act of storing nectar, which is very dilute when gathered by the bees and placed in cells, and then reducing or evaporating by fanning and cycling the air through the hive, not only cools the hive space, but also raises the humidity. (Can you say Swamp Cooler?) The challenge the bees have here with balance, is the fact that the process of rearing brood requires higher temperatures (roughly in the 90's), along with high humidity. But the act of evaporating the moisture from the stored nectar, cools the space. So too much active effort to store large amounts of honey, would drop the temperature below what is needed for brood rearing! Both processes are critical to survival but directly conflict with each other, as far as temperature is concerned. Brood rearing needs the higher humidity, so the high moisture content from reducing nectar is a bonus. However a fairly high temperature of around 90° (F) must also be maintained. This actually lends a scientific explanation behind why beehives have been observed to do slightly better out in the sun rather than in the shade (generally).
- The volume of bees in a given hive space becomes a significant factor, since it requires a larger volume to be able to maintain ideal values of temperature and humidity for a hive body that absorbs more sun energy placed out in the sun, than one placed in the shade. The same is true for a hive painted a dark color rather than a light color. So be mindful that your choices of color, placement, and actions, can significantly impact a given colony! I lost a small colony once because it was placed in a large box in the sun without shade, before it had the bee count necessary to regulate the temperature for that space and heat load. In other words, it was too warm, and the humidity too low to raise brood, and it could not thrive. The queen was laying but the eggs were not hatching! Had I placed some shade on that colony until it grew to fill the box, it might have had a far greater chance to survive. The first queen disappeared, and a second queen I purchased, tried but the eggs did not hatch and the colony died out slowly over a couple months. What I thought was a dud queen, it turns out was handicapped by my choice of placement and lack of this knowledge.
- Recent observations by WARMBEES, while studying very small colonies now surviving to spring, and trying to determine what constitutes the minimum critical mass of bees required by very small colonies to survive, has identified an additional behavior utilized by bees to raise the humidity for incubating eggs and brood rearing at a micro (sub frame) level, in spaces too large for the small colony to maintain. I call this condition and resulting behavior - HYPO-HUMIDITY SYNDROME IN CRITICALLY SMALL COLONIES. In this condition, bees will place nectar directly adjacent to, and surrounding the patch of cells with eggs, and then form a tight, living-canopy of bees over the patch of eggs and the adjacent nectar, effectively using their bodies in a tight formation like an umbrella to capture and trap higher humidity and heat in close proximity to the tiny nursery of eggs for incubation. Anyone that has observed a package or other small colony trying to survive with reduced in-hive humidity, has seen them form this tight canopy of bees, which you can't see through when looking for eggs and brood. Even when you move a few bees to look for eggs, they immediately move right back to cover the gap. This stronger affinity to cover the patch of eggs, not only helps maintain temperature under the canopy of bees, but humidity as well. Many beekeepers have seen this and even try to prevent this mix of nectar and brood with queen excluders, perceiving it as an undesirable behavior, when in reality it is essential to raise brood when the whole hive environment can't be brought to optimal humidity due to a lack of bees and resources. Eggs can't hatch, nor can larvae thrive, if the temperature OR humidity is too low! So this explains the mechanism and requirements that dictate what constitutes the minimum critical mass of bees required for a colony to THRIVE. When the bee count lowers to below what is required to gather sufficient nectar or syrup (wet feed), and place it in an adjacent ring of cells around the patch of eggs and larvae, and then to additionally form a constant living canopy over both the nectar and the patch of eggs in order to maintain a micro climate with sufficient temperature and humidity, the colony cannot raise brood to replace the dying bees, and the colony will fail to thrive and die all the way out! Here again, choices and actions of the beekeeper can have critical impact on survival. For instance, if a well meaning beekeeper sees or places capped honey from a stronger hive into a critically small colony, thinking it is better than syrup or nectar, that beekeeper has not adequately addressed the fact that the bees MUST have high moisture available adjacent to the egg patch, to evaporate and raise humidity! The better choice would be, say a 50/50 syrup which has plenty of evaporation capacity to contribute to the high humidity levels. Additionally, leaving the high permeable tops on to reduce moisture for winter, and/or open screen bottoms, during early brood rearing, is counter-productive to high humidity needs of incubation and brood rearing.
- While excess moisture during winter months is undesirable and leads to mold and other detrimental effects, sufficient moisture during critical times of brood rearing, is critical to survival. So for very small colonies, measures to optimize successful brood rearing with minimal effort for the bees to manage Humidity and Temperature, should be taken. Actions such as reducing their living space like placing them in a NUC box, or inserting foam blocks as filler in empty portions of larger boxes, or tight sealing follower board, or even adding a small container of water with a large rag wick, or similar, to augment humidity in the space, are all useful measures to aid a small colony with surviving in the spring until they can take off and actively thrive! Well meaning beekeepers placing capped honey in a struggling critical colony rather than liquid feed, or maintaining large stacks of honey-laden boxes, even after colony size has diminished to nothing, are actually frustrating the humidity portion of the equation, often more than the temperature. The same would be true of maintaining plain sugar or other dry methods of augmenting low reserves after brooding starts, in addition to keeping large spaces. These measures are fine during colder months with no brooding, but when brooding needs to ramp up, we must change the augmentation to a liquid source. Warmbees customers have an additional power-tool that can significantly change the equation by simply setting the temperature range to the high brooding range a month before brooding would normally begin. Increasing the brood season by assisting with the higher temperature management early, means earlier brood and ramp up! Where most colonies become critical in spring as bees die off before brood temperatures are attainable due to weather, the Warmbees In-Hive Warmers allow for brood, sometimes a month or more, earlier than normal, before bee counts get so critically low. Again, our choices, practices and ignorances, may have unintended ill-consequences on our subjects...
- So understanding these parameters of temperature and humidity, and the needs of the bees, at different times and environments, allows us some measures to actively assist with stressed colonies to preserve them through the winter months, and especially in the spring when humidity must drastically increase for incubation and brooding. We must consider additional measures like: smaller spaces for smaller colonies, actively adding humidity with a small vessel of water with a rag as a wick, and liquid feed available when higher humidity is needed. The placement and color of hives in direct sun, or temporary shading as needed, proportional to the bee count and size of colony, also might be taken into account. Or perhaps a combination of these, and even injecting more bees by caging the small colony under a push-in screen cage, and adding a frame of bees and capped brood from a stronger hive, as I have used all of these methods several times, to successfully turn this HYPO HUMIDITY SYNDROME around. These and other methods yet to be identified, can drastically improve the chances for colonies with HYPO-HUMIDITY SYNDROME AS A CRITICALLY SMALLCOLONY.
- Warmbees In-Hive Warmers are being very successful in helping to manage temperatures internally, which in turn, often presents us with smaller surviving colonies that would have otherwise been dead-out statistics, but which we must then take more active measures to monitor and manage. For many beekeepers, the diseases and other issues which Varoa brings to the table, weakens the colonies making them ill-prepared for winter temperatures which, I believe, to be the true reason behind the higher winter losses of recent years. However with Warmbees In-Hive Warmers, now many of these weaker hives are surviving, which gives us additional time to medicate and perform other actions to combat disease. But hey these are good problems, since we now don't have to purchase replacement packages as often! Can you say "I just got my money back on my investment in my WARMBEES In-Hive Warmer"? My last package was $125.
We've heard many beekeepers say that colony survival is mostly due to genetics, and if they can't make it on their own, then let them die so that better genetics and behaviors can prevail... Of course those who harbor this opinion live in a perfect world and have never needed any vaccinations or help from any doctors to survive, simply because their own superior genetics doesn't require such nonsense! Consider that our methods and choices can be part of the problem as well as the solutions. If we consider ourselves highly evolved, and of near perfect genetic makeup, have we then never been caught off-guard by a storm or an odd season, or a drought, or combination of these? If your answer is "never", then we bow to your beliefs and methods and superior genetics... But if your answer is yes like the majority of us, then you'll recognize that situations can arise that can seriously impact survive-ability of good people... I mean bees... in spite of perfect genetics! We humans simply put on a coat when caught if it storms (a wonderful invention), or see a doctor when sick, and yet deny similar things to our bees in the name of poor genetics... Meanwhile our losses increase... EndOfRant
THINKING INSIDE THE BOX (HIVE): THE PHYSICS OF WARMING/OVER-WINTERING BEEHIVES
LUCKY FOR US: The laws of physics are pretty much fixed and don't sway to opinion or banter. Understanding how temperature, humidity, pressure and volume all apply to us and our world, and particularly to our interest in honeybees, is easily within our grasp and follows the laws of thermodynamics, which are pretty much set in stone. The following is some fairly simple information (It just looks a little busy) that will help us help our little friends, and educate anyone interested, to be able to successfully overwinter honeybees regardless of genetics or opinions, if it is to be possible:
Some SIMPLE un-alterable LAWS of THERMODYNAMICS:
- Conservation of Energy: Energy cannot be created or destroyed, but can be converted into different forms. The SUM of all energy forms is constant. We will consider any beehive to be a container of fixed volume with fixed dimensions and made of standard materials, therefore there are clean equations that we can use to show what it takes to achieve equilibrium at a desired temperature value for that space and environment.
- Heat Flow and Equilibrium: Heat energy will flow only from a hot object to a cold object. If two objects are in "THERMAL EQUILIBRIUM" (are at the same temperature) no heat will flow between them. Heat flows at a rate proportional to the thermal coefficient of the materials through which the heat is conducting, multiplied by the surface area, the depth of material, and the difference in temperature, otherwise known as: - The FOURIER'S LAW OF CONDUCTION. This equation is really quite simple as given here: q=UA(dT) (Confusion alert: This equation can be in three forms... the above is in terms of "U" which stands for the conduction of heat, while in step 4 below, it is written in the forms, which are either in terms of the Resistance of heat, like the second form shown in step 4 below, or in sub terms using k and L. The following steps 3 through 8 are only going to describe these terms, and then show that we must first compute the U or the R value using some easy additional terms like k and L, prior to entering it into one of these simple equation forms!)
- (q) or heat flow is either labeled in BTU/hr or Watts. U (stands for thermal conductance, also the same as k/L, and is the inverse of R which stands for thermal Resistance). k=coefficient of thermal conductance of a material, and it's units are BTU/hr-Ft²-ºF (English), or Watts/mK (metric), and can be found in many reference tables for most materials. L=Thickness or length of material in feet. A=area in Ft². T=temperature in ºF. The term dT is just a short way of saying Delta Temperature, or the difference in temperature, (in this case between outside and the inside temperature Ti-To).
- Fourier's Law of Conduction very simply is: q=kA(dT)/L. Some additional information is that R (thermal resistance) is also known as the R value of insulation that you see on the package when purchasing insulation, and is related to this equation as R=L/k and is the same as 1/U, so another form of the Fourier Law of Conduction (substituting R for theabove is q=A(dT)/R and is also the same as q=UA(dt). I told you it was simple! These are three forms of the same equation depending on weather you want to focus on the Resistance or the Conductance of heat.
- How does this apply to Beekeeping? As I said above, if we consider a hive to be a finite space bounded with known material and thickness, and if we negate considerations of convection internally by managing ventilation and windbreak, then we can generally place a number on the HEAT LOSS of a hive during any given temperature condition, and therefore the amount of HEAT REQUIRED to maintain a reasonable equilibrium, and by extension, a live hive!
- What this means to us is that there is no need to guess about what it takes for a hive to survive. We know the materials that our hives are made from, and how thick they are, and can quickly calculate the total surface area of the hive. Given the R factor of those materials and the necessary internal temperatures needed or desired, we can calculate the amount of energy that the bees must generate to remain alive for any given outside temperature and materials used to construct the hive. This knowledge empowers us to basically know what preparations we must make for a given set of expected temperatures, or conversely what we can expect with, or the limitations of, the preparations that we have made.
- One more equation related to conductive heat transfer is: 1/U=L1/k1+L2/k2+L3/k3...+[1/h(i)+1/h(o)]. So here U (conductance) is calculated including, and accounting for, each material layer comprising the total length or depth (L) of the sides and top and bottom of a hive, which are added separately, and then with the final addition of the inside Film coefficients (h) of both the inside air and outside air, (the [1/h(i) + 1/h(o)] portion above). FYI - The Film coefficient of still air is 1.7 BTU/hr-Ft²-°F, while the Film coefficient of air moving at 7.5 mph is 4.0, and for 15 mph is 6.0.
- Another way of looking at the Fourier's Law of Conduction equation is using the Resistance form. Since R=L/k, then 1/U=[R1+R2+R3...+1/h(i)+1/h(o)]. Simply this means we add up the R values of the materials for a total R value, plus account for the difference in film coefficients of air, with wind chill, for both inside and outside the hive. (for an example: the wood from the hive itself and a 1" foam insulation board snugly applied). Some useful info - the R value of 1" pine is=1.383, the R value of 1" foam insulation is R5 and 2" foam is R10. The total surface area of a full deep Langstroth hive box is 4.82 ft² with a pine top and bottom combined area of 4.58 ft². The area of a Langstroth super is slightly less at 3.422 ft². So to simplify for our purposes: R(1" pine)+R(1" Foam)+1/1.7+1/1.7 gives R1.383+R5+1/1.7+1/1.7 yields a total of R=7.5594 or a U (Don't forget it's 1/R) of .132284 BTU/hr-ft²-°F for a calm day. Simply, Conductance (U) is the inverse of (R)esistance.
- So knowing the overall R value from above 1" foam and 1" pine example, and for an example of zero °F outside with 40°F inside, we apply this to our Fourier Law: For a typical hive with a single Langstroth Deep, with a single Langstroth Super - Area(total) (A) is 4.82ft²(Deep)+3.422ft²(Super)+4.58ft²(Combined Top and bottom) = 12.822ft²(total). Fourier Conduction Law yields: q=A(dT)/R(tot) = 12.822x(40)/7.5594=67.847 BTU/hr. The conversion to Watts is 1 BTU/hr=.29307107 Watts, therefore is equivalent to 19.884 Watts of heat energy being lost or conducted from inside to outside per hour through the walls and top and bottom, which must be made up to maintain equilibrium. It also turns out that a full box and a half of bees can generate 15 to 20 Watts of energy by consuming the high calorie honey and converting it into heat energy. Judging the strength and health of your colony empowers you to roughly estimate how much insulation you might need to add, to maintain equilibrium, bringing the heat needing to be generated by the bees, down to within reach of your colonies ability. The result is SURVIVAL! Adding a critically controlled Warmbees In-Hive Warmer, with Add-on element board, which combined is capable of 24 Watts, just made it possible for your bees to exceed zero °F with little or no stress, and possibly -50 °F with 2" of foam insulation instead of 1".
- This example and the physics behind it, are based on a snug fit of the insulation, which removes any convection between the layers being accounted for above, and minimizing any other convection paths from the inside of the box to the outside. So just like a huge open window in your house can let all the heat out, effectively negating all the insulation of your walls and materials, large vents and permeable tops can do the same to a hive structure. For a typical Langstroth or Warre hive, shutting down the entrances to only about an inch, accomplishes a minimal convection path. The bees will often use propolis to shut them down even further to what they want. Convection is an extremely effective method of heat transfer and must be managed to a minimum! Convection being used in beehives either for heating or other purposes artificially, is extremely detrimental to bees so using fans in an attempt to get heat in the box are bad. This constitutes an extreme irritation if not deadly condition for bees, which is why they will attack or otherwise reject its use. Convection dries the air and seriously impacts humidity, which they tightly control. Convection external to the hive during winter, basically negates other methods of winterization. In other words insulation that is not tightly or snuggly applied, is nearly ineffective at aiding the bees in survival. In fact convection acts like a pump in moving air which from the windchill portion of the equations above, can actually make things worse. An example might be heat tape wrapped around a hive with good intentions, followed by a wrap of tar paper. If air can move between the tar paper and the hive, then heat rising from the heat tape, draws the super cold outside air in the bottom, effectively raising the heat loss in at least the bottom box. The heat from the tape is drawn up the chimney and away from the hive rather than lingering and contributing to the conduction into the hive as intended.
- Windbreak is another tool for aiding the minimization of convection in stripping heat away from beehives. Obviously forced air from any source is like making a small window into a large one, and now even small vents can be too much for the internal heat source to keep up. So hives in windy areas will have their chances for survival drastically improved with windbreaks. Many will often stack some hay bails around a hive or group of hives to help accomplish a windbreak. Others use something like Tar paper to wrap a hive. It must be emphasized that while windbreaks help reduced forced air through the small entrances and vents, they do very little toward the insulation of a hive. It is thought by many that Tar paper wrap is adequate preparations for winter. If you live in a mild winter zone, maybe. However while it may add a bit of solar heat during the day being a black light-absorbing color, it does nothing at night! And we know that winter means longer nights than day. If the bees die at night, it really doesn't matter if they were warmer during the day! Your winter preparations must provide for protection against extreme elements 24/7 with no lapses. Tar paper can aid as a windbreak but does very little more.
- Choices of winter feed supplements should be examined a bit in light of our equations... If we stop down the sources of convection to minimize large heat losses, then adding liquid feed can become a larger problem with regard to excessive moisture, leading to mold and mildew. Since honey has already been reduced and capped, thereby not adding to excess moisture, it is the ideal storage medium. This is an example of genius in nature, and one of the reasons we are in awe of honeybees! If we are to attempt to even come close while supplementing weak stores, then we need to reduce liquid feed to a thicker honey like or light caramel consistency, to minimize adding excessive moisture. Adding granular sugar known as the "Mountain Camp" method, or prepared sugar bricks such as "Laurie's Recipe" on Beesource.com are better for the colder climates where entrances and vents need to be made smaller, to reduce excess moisture.
- While bees maintain their internal space at a temperature of their own choosing if possible, which if that temperature choice is above the setting of the Warmbees In-Hive Warmer, there may be little or no benefit beyond being ready in case they struggle. However if the warmer is configured to put out a minimum of 10% heat with the B.A.W.B feature (In-Hive Warmer II), or if, or while the warmer is configured for brooding temperature range, it stands to reason that any heat provided by the Warmbees In-Hive Warmer, is heat that the bees need not consume honey to burn calories to generate! This translates to DIRECT SAVINGS OF HONEY! Hence the term - "Buy Another WarmBees" or B.A.W.B. With Honey at just $5 per pound, it takes only 17 pounds of honey saved, to equate to the cost of a Warmbees In-Hive Warmer. Customers often report hives using up to half of the honey they normally require to get through an average winter, contrary to many uninformed opinions! Additionally, they nearly always report stronger hives in the spring which equates to more bees earlier in the spring, prior to nectar flows, which adds additional honey to the pot. And if that's not enough, add the fact that colonies now survive that otherwise die out, and you save the cost of a replacement package, which was the original goal. I have created NUCs in the spring with only a single frame of eggs and bees, with a Warmbees In-Hive Warmer. Two frames works better, but it can be done with less than the traditional 3 frames usually needed, which allows for faster growth in an apiary. This is where some of the research was done that lead to the discovery of what constitutes a critical mass of bees necessary to thrive which I now call the HYPOHUMIDITY SYNDROME in MASS-CRITICAL COLONIES. So Warmbees In-Hive Warmers allowing for smaller NUCs is a welcome additional benefit, but this benefit is maximized with knowledge presented inStep 5, way above near the top of this KNOWLEDGEBASE, in the "TEMPERATURE AND HUMIDITY ELEMENTS FOR SURVIVAL" section.
- All said and done, a Warmbees In-Hive Warmer, can often pay for itself multiple times in its first winter, and with the equivalent of multiple times for every winter in the lifetime of a warmer, it is one of the greatest product values out there. And the greatest savings come from the largest colonies, not the weakest colonies that are being saved. Go figure... NOW FOR THE PROOF IN THE PUDDING...
OPTIMAL WINTER CONFIGURATION:
Now given the above information on Humidity, and Heat Loss dynamics, we are armed with the knowledge to manage our hives appropriately for the colony size of each hive, and better able to configure the hives for optimal success against winter losses! I will start with a real-life example that I recently examined after a Warmbees customer, which had purchased 4 In-Hive Warmers, still had hives die this last winter... The customer had indicated that they did better than his other hives and previous years and so was still happy with the warmers, but sadly they still did not make it through the winter. This, however to me, indicated that there was another significant reason for the failures, since most reports from customers are that hives with Warmbees In-Hive Warmers, remain alive when other hives without, don't! I began to ask several questions, and from the answers, it still was not obvious. However this customer did include a photo of his apiary...