Why Did My Beehive Die Last Winter?

Pinterest Hidden Image

Losing colonies is a big deal to any beekeeper. It is especially upsetting to feel that you have done everything right – yet you still lose hives. The most difficult time for honey bees is during the cold months of Winter. There are several reasons beehives die in the Winter. Some of them can be overcome with good beekeeping practices. Yet, the truth is that we sometimes don’t know what went wrong. This give us the incentive to do everything we can to give our colonies the best shot.

Two beehives in Winter snow with inset of frames from a dead beehive.

A healthy beehive with good honey stores should be capable of maintaining bees in residence until Spring. An important part of good hive management is making sure you have done your part to see that your colonies are ready before cold weather arrives.

Top Reasons Beehives Die in Winter

The more facts about honey bees that we learn – the less we know. At least, it seems like that at times. However, when we look at the issues that are common in failed Winter beehives – we do see some common factors.

  • extreme cold temps
  • small bee population
  • starvation of the colony – lack of adequate food
  • condensation inside the hive – not enough ventilation

Extreme Winter Cold

Extreme cold temperatures play a role in the death of some Winter beehives. In regions with long Winters and frigid temperatures, beekeepers must learn how to winterize their beehives properly.

Honey bees are insects (cold-blooded insects). If their body temperature drops too low they become sluggish and unable to move. Unless the bees become warm quickly they will die.

A healthy colony with a good population of workers and enough food can ride out the cold months.

Honey bees survive Winter by forming a cluster of bees inside the hive. They consume food and generate enough heat to keep body temperatures at a sustainable level.

But even in the best cases, an extremely cold season can result in more dead colonies than would be expected in a normal year.

Small winter cluster of bees in danger of dying due to low population.

Winter Deadouts – Due to Small Colony Size

Because honey bees reproduce (as a family unit) in a cyclic manner, colony populations will vary through out the year. Larger populations in the late Spring and Summer will fall to smaller Winter populations.

This is normal bee behavior and mostly related to the genetics of the hive. Some breeds of honey bees over Winter in a larger cluster-while others naturally have fewer workers in the Winter hive.

This presents advantages and risks. A large bee population is an asset for creating heat for survival. However, they will need more food to last until Spring or face starvation.

A colony with a very small population, faces the risk of the bees not being able to survive Winter’s cold temperatures. During extreme cold snaps, some of the bees on the outermost shell of the cluster may die.

Join Our Beekeeping Community

Free "Secrets to Successful Beekeeping" plus weekly newsletter with info about bees, beekeeping and more...

If another cold snap arrives right away, the colony is now trying to survive with fewer bees than it had before. When this happens repeatedly, it takes a toll on the population – and may result in the Winter death of small colonies.

Winter cluster of bees at the top of the hive stack.

Starvation – Usually Due to Lack of Accessible Food

More colonies die from starvation in Winter than any other cause. Do I mean that the bees did not have enough honey to last until Spring? Yes, that is often true.

But, a honey bee colony can starve to death with boxes of honey on the hive! Normally, the outer edge of the cluster stays in contact with cells of stored honey. Throughout the cold months, the cluster slowly moves a bit to remain in contact with food.

A larger cluster (bigger population) has the energy (heat) to move at cooler temperatures than a small cluster. If a prolonged cold wave prevents the bees from moving to food, they become unable to generate heat and freeze.

Even though they did succumb to the cold, it is a lack of food that caused their deaths. So starvation is the culprit. 

They will starve in place on the comb – usually with their heads stuck in the cells. Yes, your bees can die with a full box of honey on top-but just out of reach.

Why the Winter Cluster Does Not Move

The Winter cluster is formed by thousands of bees moving close together in the hive. They create warmth by vibrating their flight muscles.

Their shared body heat is able to warm the cluster enough to sustain life – but not to heat the entire interior of the hive. A bit of slow movement is possible. Warmer days allow the cluster to reform near food.

But, if a cold polar vortex crosses the country and swings far to the south, the bees may find themselves stuck in place. Days of extreme cold may prevent cluster movement.

In addition to very cold weather and a small population, there is another reason bees may not move to food. If they have brood or bee larvae in the center of the cluster, they will often NOT leave the brood to reach honey.

What can a beekeeper do? We can not control where the cluster moves – or not. However, we can make sure our colonies are well fed before Winter.

Condensation Kills Beehives

Too much moisture inside the Winter hive is a serious problem. In truth, some regions of the country have more problems with hive condensation than others. This is another instance when your climate plays a role in your colony management.

Where does this excess water come from? A cluster of live bees, eating honey and generating heat, gives off moisture. The warm moisture rises to the top of the hive.

If the temperature is very cold outside, moisture can condensate on the underside of the hive top. This causes water to drip down on the bees. Most of the time bees can cope with cold temperatures. But wet, cold bees are dead bees.

Some beekeepers use quilt boxes for their beehives and other strategies to absorb excessive internal hive moisture. I have not needed to do that in my area. However, it may be something to consider for your hives if you live in a damp or very cold region.

Candy board, quilt box and combining beehives all strategies for preventing beehive death in winter.

Tips to Lessen or Prevent Winter Hive Losses

We can not control all aspects of beekeeping. But, here are some tips to help reduce winter beehive losses.

This is where I rely on my beekeeping journal and notebook. I may not remember what I did in each hive for Winter prep-but my notes will remind me.

  • control varroa mites numbers – keep colonies healthy
  • evaluate brood patterns in early Fall – replace sub-par queens
  • combine colonies with very small populations before Winter
  • ensure that the hives are well stocked with food
  • wrap hives if needed for your climate but remember ventilation

Monitor Varroa Mites

Throughout the season – and certainly well before Winter – perform testing – varroa mite counts and treat your hives if needed. Colonies with high levels of mites have adult bees that are not healthy and live shorter lives.

The nurse bees in the hives are also not well enough to raise the longer-lived fat Winter bees needed by the colony. Don’t assume your colony is good – check them.

Evaluate Brood Patterns – Requeen if Needed

If the queen is not laying a good pattern in late Summer, it may be time to consider requeening the hive. (Assuming you are not in a nectar dearth – when even a good queen will slow down egg production.)

Take Your Losses in the Fall – Combine

If you have a couple of colonies that are very low in population – consider coming the two hives into one. It will have a better chance of Winter survival.

Check Food Stores Throughout the Winter

In addition to proper Fall feeding for your hives, peek inside to check food stores in mid – late Winter.

Feeding bees in winter is more difficult. But it can be done. The beekeeper may make candy boards for the hive or employ other ways of feeding such as sugar cakes.

To Wrap or Not

You may decide to wrap your hive to provide a bit of extra insulation. But, not all beekeepers need to wrap up hives during Winter.

If you live in an area that benefits from hive wrapping, (check with your local beekeeping association) be sure to allow for good hive ventilation. Even a Popsicle stick on the top box will raise the outer cover up just enough to allow air flow.

FAQs

How can I determine if my hive is at risk of dying over Winter?

While there are no guarantees, good preparation in late Fall is a good start. Check for a sufficient population size, ample food stores, and signs of a healthy queen.

How many bees do you need in a hive for Winter?

Bee genetics and colony health play a role in the cluster size needed to keep the colony alive during Winter. Climate is also a consideration as it affects how low the thermometer drops and the duration of cold. Each hive is different.

Can my beehive starve to death even if it has honey in the hive?

Yes, a beehive can starve even with honey left in the hive. If the cluster size (colony population) is very small – they may not be able to reach stored honey during prolonged cold spells, resulting in starvation.

How can I prevent condensation inside my beehive during winter?

Excess moisture can build up inside your beehive if adequate ventilation is lacking. Some beekeepers use quilt boxes or other strategies to absorb moisture.

Final Thoughts

A healthy colony of honey bees with ample food stores should live from one season to the next. But, in recent years, the percentage of honey bee colonies lost over Winter has grown. Our colonies are struggling to deal environmental issues, as well as, new bee pests and disease.

Those colonies that come through Winter in good shape are highly valued. Perhaps, those bee genetics are some that we want to keep in our apiary.

Resources

Leave a Reply

Your email address will not be published. Required fields are marked *