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.
- 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!
- Temperature also affects the lifespan of the honeybee. During summer months, the lifespan is typically 6 - 8 weeks. However during cold months, dormant temperatures, (inside 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, they gather and store nectar, which is very dilute when gathered, but then it is reduced by evaporation as it is fanned by the bees. This not only cools the hive space, but also raises the humidity. Can you say Swamp Cooler? The bees maintain an ideal balance of temperature (90°) AND near 100% humidity, which is required for the process of rearing brood. This explains why strong colonies have often been observed to do slightly better out in the sun rather than in the shade. With adequate bees for the volume of space, the bees handle the warmer temperatures of little to no shade very well. However beekeepers placing very small colony in a full box or hive out in full sun without shade, is a setup for disaster since the colony doesn't have enough bees to manage the extra heat. The answer? Rather than place colonies in permanent shade, place them out in the sun, and then build or place temporary shade if needed, until colony is sufficiently strong. Bearding is evidence that they are too warm.
- The volume of bees in a given hive space is a significant factor for both Winter and Summer. It requires a larger volume of bees to be able to maintain and manage ideal values of temperature and humidity for a hive body that absorbs more sun energy placed out in the sum than one placed in the shade. The same is true for a hive painted a dark color rather than a light color. It also requires more bees to heat a larger space in the winter. So be mindful that your choices of color, placement, and actions, can significantly impact any 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. 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 and/or temperature, 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. This is why we often see nectar or honey in the outer edges around brood patches.
- 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 space 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! 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 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, the colony cannot raise the 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 have critical impact on survival. If a well meaning beekeeper sees or places capped honey from a stronger hive into a critically small colony, thinking it is all that is needed, that beekeeper has not adequately addressed the need to have high moisture available adjacent to the egg patch, to evaporate and raise humidity! Liquid feed is the better choice.
- While excess moisture during winter months is undesirable and leads to mold and other detrimental effects, sufficient moisture being available during brood rearing is critical to survival! 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 to match colony size, 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, 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 when its time for brood rearing, rather than liquid feed... or maintaining large stacks of honey-laden boxes, even after colony size has diminished to almost nothing, are actually frustrating the humidity portion of the equation , often more than just temperature. The same would be true of maintaining plain sugar or other dry methods of augmenting low reserves after brooding starts. 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.
- Understanding survival factors of temperature and humidity, and how these relate to the hive space in relation to the colony size at different times and changes of environment, allows us some opportunity 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 carefully consider all these measures and actively manage them. 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, are important. These, together with the placement, size, and color of hives, in direct sun or temporary shading, are all decisions and factors based on bee count and size of colony. 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. We have many options that we can use to drastically improve the chances for colonies with HYPO-HUMIDITY SYNDROME in CRITICALLY SMALLCOLONIES.
- 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"? The last package I purchased was $130.
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 problems 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 in 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 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:
HOW TO CALCULATE HEAT LOSS IN BEEHIVES
(THE FOLLOWING IS NOT AS HARD OR CONFUSING AS IT MIGHT SEEM AT FIRST! HERE COMES A TINY BIT OF EASY MATH)
First we need to understand Heat Flow and Equilibrium:
Heat energy will flow only from a hot object to a cold object (air is our object). If two objects 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=kA(dT)/L (CONFUSION ALERT: This equation is easy to understand once you understand these terms. This same equation can also be written in three different forms - (explained below)... it is important to understand that the term "U" is equal and identical to (1/R) and also equal and identical to (K/L). The following steps 1 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! NOTE: This "R value" is what you most often see when buying insulation or foam etc., from stores and is the form we will use)
Second, we must understand these terms:
"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" is the coefficient of thermal conductance of a material (just a number you look up in a table for each 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 - subtract the lower from the higher).
- Fourier's Law of Conduction very simply is: q=kA(dT)/L written in terms of the coefficient or number for the rate of heat flow through a given material (k) and the thickness (L) of that material. A second form of the same equation is q=UA(dT) and is written in terms of the conduction (symbolized as "U") of heat through a material. The third form of the same equation is q=A(dT)/R and is written in terms of "R" (thermal resistance), and 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. I told you it was simple! These are three forms of the same equation depending on weather you want to focus on the Resistance to the flow of, or the Conductance of heat.
- 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 more importantly, the amount of HEAT REQUIRED to maintain a reasonable equilibrium to keep a live hive!
- 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 must be generated to survive for any given outside temperature and materials used to construct the hive. This knowledge empowers us to 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 (h) (like the coefficient (k) above, is just a number and can be found in reference tables, and for 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.
- To calculate the heat loss of a hive, we will be using the Resistance form of the equation. We begin by first calculating the R for each layer of material. R=L/k. R must account for any insulation we have added to our hive surfaces and the material the hive is made from. 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. Now for an example: (the wood from a hive constructed of 1" pine and a 1" foam insulation board snugly applied in still air). First 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 yield a combined area of 4.58 ft². The area of a Langstroth super is slightly less at 3.422 ft². The thin film coefficient (h) for still air is 1.7, so to simplify for our purposes: R(1" pine)+R(1" Foam)+1/1.7(inside)+1/1.7(outside) 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. Now we simply plug this value into our equation...
- knowing the overall R value for our 1" foam and 1" pine example, and for an example of zero °F outside with 40°F inside (dt=40-0), we apply this to our Fourier equation: For a typical hive with a single Langstroth Deep, with a single Langstroth Super - Area(total) is: A= 4.82ft²(LangDeep)+3.422ft²(LangSuper)+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 multiplying our 67.847 X .29307107 give us the equivalent of 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 required by the bees down to within reach of your colonies ability. The result is SURVIVAL! Adding a critically controlled Warmbees In-Hive Warmer, and perhaps with with an Add-on element board in the coldest areas, would combine up to 30 Watts in addition to the heat produced by your colony, just made it possible for your bees to exceed zero °F (1" insulation) with little or no stress, and possibly -50 °F with 2" of foam insulation".
- 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. 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...