How much should you feed your bees? What are their requirements? Unfortunately, there is no simple answer since temperature ranges and food abundance differ from one area to the next. The goal of the article is to provide some research perspective on the honey bees’ energy output. We will focus on the feeding requirements for the winter mainly, but overall provide a broad understanding of feeding throughout the year.
Feeding requirements and honey bee nutrition have been studied in the past, but since the large loss attributed to CCD(Colony Collapse Disorder) in 2008 – more attention has been on honey bee nutrition (as well as factors to rethink the way we are caring for honey bees beekeepers).
Regarding what honey bees need regarding nutrition, I thought this article put it well:
“Honey bees require carbohydrates (sugars in nectar or honey), amino acids (protein from pollen), lipids (fatty acids, sterols), vitamins, minerals (salts), and water. Additionally, these nutrients must be present in the right ratios for honey bees to survive and thrive….” (Feeding Honey Bees)
Plain and simple, Honey Bees get the best nutrition from natural foraging. Using sugar syrups or pollen substitutions should only be used as a tool with a concise start date and end window.
A beekeeper will need to assess their region, seasons, and blooms to get a picture of available food sources. Try to out when nectar, pollen, and water are readily available in your area and when they are scarce. The key is only to supplement feeding if the colony’s health is in jeopardy. No more, no less.
The only times you may want to feed your honey bees are late winter/early spring and late fall. Michigan State University did a good job providing an overview of the feeding honey bees, which can be read in their article “Feeding Honey Bees”.
Lets focus on winter feeding. For our area, different beekeepers go into winter with different configurations. We found that going into winter with a single deep Langstroth hive was appropriate for our region. A typical winter colony of 17,500 bees survived -25 C for more than 300 hours (Corkins 1930). (Temperature Control in Honey Bee Colony)
To give you some perspective, a smaller colony of 17,500 bees, which you would find in a crowded NUC, was able to survive -13F for about two weeks. This helps to understand the survivability of honey bees. They are able to endure pretty harsh winters.
What about energy usage? Do honey bees need large supplies of winter stores? Notice what a research paper said on the subject.
“…They investigated the behaviour and the sugar usage of bees kept in cages in the laboratory at different environmental temperatures. It was shown that at 10°C 99% of the bees clustered together, at 15°C 80% did so, and at 20°C less than 50% clustered. The energy use was lower at 10°C than at 15°C. According to literature bees start clustering around 13,9°C (Corkins & Gilbert, 1932).”
Why was the energy use lower at a lower temperature? Because honey bee’s energy requirements are less during the winter. The inner cluster is fairly active during the winter, while the outside of the cluster – depending on the temperature – reaches a state of torpor. As a whole, during colder weather, their metabolism drops, and they require less food.
So the more active a colony is, the more energy use they need; the colder it gets, the less energy is used, respectively.
Of course, if it starts getting very cold, energy usage starts to increase again since the honey bees have to keep their brood and center cluster warm. As temperatures fall below around 10 F, the honey bees start increasing their energy output. In areas like Canada, wrapping would be helpful or storing the hives indoors. In our area, we get very few days during the winter that fall below this, compared to other areas farther up North.
This helps understand that food usage is lower during the winter and higher during non-winter months. When honey bees are in the middle zone – it can also be dangerous. Long spells of temperatures around the 50s with heavy rain can be tough on bees because they can burn through their stores quickly.
A research article made this very clear:
“From the observed energy consumption of the bees in the cluster the authors calculated the amount of consumed honey (80% dry matter) per bee per day. At the low temperatures (3°C) the use was 2,6 mg per bee, at 13,5°C (start of cluster formation) 6 mg per bee per day. Calculated for a cluster of 10,000 bees this translates at 3°C to 26 gram/day, 780 gram per month, and 4.7 kg for a winter of six months length. At the higher temperature (13,5°C) 60 gram/day, 1800 gram/month, and 10.8 kg/winter. The conclusion that a frugal beekeeper and his bees are more at risk in a winter with many days above 10°C appears to be fully valid. The calculated amount of honey needed in a mild winter (10.8 kg) is not too far from the generally recommended amount of 14 kg sugar syrup for a normal sized colony. ” (The Honeybee winter cluster…)
In other words, a cluster of 10,000 bees (about 3 pounds or in a NUC) needs 10.36 pounds of honey to last them six months at 37.4F. So, at a minimum, a NUC needs less than two frames of honey to survive winter – or winter with a constant temperature of 37.4 degrees.
Let’s covert this research into more practical means. In our area, yearly temperature averages range between 20F to 90F. In our area, a NUC unwrapped (but protected from winds) can survive and thrive. We, again, recommend a single deep going into winter.
This translates to about 3 – 4 frames of honey in a NUC and 5 – 8 frames in a single deep to last a harsh winter. So, in our area, two deeps or more going into winter ends up being a liability to the honey bees – since they have a lot of space to warm up(heat rises into the top deep, and unfortunately for many who have top ventilation – there goes your heat), and due to their increased size – the Varroa population is higher. (more bees, more varroa, fewer bees, fewer varroa – semi oversimplified, but accurate.) You can consider our other article on this subject: Winterizing Beehives.
Charles Owens did pretty extensive research on honey bees exposed to the cold. He ran a 5-year experiment utilizing winter bees and doing some experiments placing honey bees in a refrigerator and running cluster, temperature, and food tests.
He used what would be considered today as three medium hive bodies colonies in his experiments. Three different situations were used, a none insulated hive, an insulated hive, and a hive that had a warmer.
With these experiments a few key points to take away.
- Honey bees do not regulate the heat outside the cluster. So, since heat rises, a smaller box with a cluster of 25,000 honey bees would do better than clustering in a larger hive.
- An insulated colony will have a less compact cluster and will fluctuate in size more. This helps understand that a cluster in an unprotected hive will utilize less food than an insulated hive. On the other side, an uninsulated colony cannot withstand long time periods in tight clusters. One test in the refrigerator that mimicked the mean temperature recorded in International Falls, Minn, which on average has the coldest winters in the United States showed that an unprotected 3-tier hive lived for 18 weeks (4.5 months). The mean temperature was 6F. The temperatures ranged from -25 degrees to the highest of 33 degrees. This helps paint a powerful picture that honey bees can survive in very harsh climates – without wrapping. The test revealed that a lack of honey and pollen stores killed them, not the cold. They died due to starvation, not cold temperatures. So depending on the length and temperature in your area, perhaps wrapping would be appropriate.
- Also, brood rearing is similar in both an uninsulated hive and insolated hive. An insulated hive starts a few days earlier, but the uninsulated hive catches up when the warmer weather arrives.
You can read the full research article titled “The Thermology of Wintering Honey Bee Colonies.“
I think this research was very powerful and cleared a lot of misconceptions on food reserves during winter and spring. I think it’s important to remember that overfeeding can be just as harmful as underfeeding. Feeding should only be done as a tool to halt starvation – otherwise, allow the honey bees to gather stores from nature sources – it’s cheaper on the beekeeper – and healthier for the bees. It’s a win-win.
What’s the takeaway?
Use feeding only as a tool to halt starvation – allow the honey bees to gather their stores and food for increased health benefits. A healthy hive is a strong hive. When we add a super for honey, and after the flow ends, we remove those honey reserves from them – this could be a problem. As long as there is food to gather, they will be fine. Suppose food halts many times in the summer during a shortage due to their increased energy output. In that case, this can put them in a bad situation. So either harvest early or harvest late. Don’t harvest close to dearth periods.
It’s good to take notes of all your hives. If hive one is low on food and a cold spell and bad weather comes through for many days (let’s say during the spring), this would be a good time to think about supplemental feeding. Late winter and early spring are the most crucial times to think about supplementary feeding. Otherwise, an early harvest, a late harvest, or no harvest.
I don’t think it can be understated. Trust the honey bees that they know more about their hive, health, and home than we do. Observe what they are saying. The research we find out is old information to the honey bee and new information to the beekeeper.