Surviving The Winter with Minimal Bee Losses in the Apiary
It has been an exceptionally warm winter in WNC. Since the fall of 2019, the average monthly temperatures have been 2° above normal. January and February are usually the coldest months. Average lows here at 3500’ range between 28° to 31° with high’s in the low 40’s. We had in the last four weeks continuous days of 50° to 60° weather.
Bees do not hibernate. They go into a form of stasis and cluster around the queen. Their sole purpose is to keep her royalty warm and alive for the coming spring. Because of the cold, rarely would these worker bees venture out of the hive and if they did, it would be for cleansing flights (read: bathroom breaks) and these would be very short in duration lest they die of exposure.
Winters clusters begin to form when the outside temperature begins to fall below 57°. The cluster is not of uniform density. The bees in the center of the cluster are moving freely, eating and performing hive duties. I’ve recorded outside temperatures in the single digits, yet it will be 92° in the center of the cluster. The interior bees vibrate their wing muscles to create heat. When the queen begins laying eggs in January, the attendant nurse bees will further regulate the temperature in the brood chamber by signaling the cluster to expand or contract. Expansion occurs to increase airflow which cools the “nursery.” If it becomes too cold, the word goes out, the cluster contracts, airflow is diminished and the temperature rises. The outermost bees form a very dense and tight mantle. These mantle bees become so cold; they appear lifeless. However, in a manner not entirely understood, they are eventually pulled and pushed into the center cluster by interior bees who then replace them and the cycle begins anew. All this activity and heat generation requires energy. Energy requires a diet high in carbohydrates. Luckily they have one of the highest sources of carbs on the planet: honey. I winter my hives with a minimum of 50 lbs of honey. This is usually enough to keep hives located in the Southeast alive until the spring honey flow.
After the winter solstice on December 21, daylight increases by one to two minutes a day. Longer days and warmer temperatures have a profound effect on the hive. The queen starts ramping up egg-laying. If it’s warm enough for sustained flight (64°), scout bees will look for nectar that won’t appear until at least March. It was 74° last Monday. To have such high temperatures the third day of February is all very confusing for the bees. They think it’s spring and eat more stores of honey to sustain even greater activity. Via a WiFi hive scale, I’m watching the bees in one hive consume 3 lbs of honey a week. This presents an issue for the beekeeper. If the bees don’t have enough honey, they will starve to death before the spring honey flow. In anticipation of a warm winter, I deliberately stored ten full honey supers last fall. This would act as a reserve for any hives that were low on honey stores going into 2020. I am down to my last two honey supers and if necessary, will be further supplementing the hives with sugar fondant.
“Take your winter losses in the fall” is a common refrain among beekeepers. Starting last August, I began consolidating weaker hives with stronger ones. This involved killing subpar queens of weaker hives that wouldn't have survived the winter. I then combined the survivors with stronger hives. This reduced my colony count from 85 to 75. The total going into November included 11 marginal hives which I left alone. I had hoped they would survive the winter months. I have since lost nine of those. Historically, beekeepers would expect normal winter losses of 10-20%. But, the industry is experiencing a new construct. An 11% winter loss of my livestock isn’t bad given last year's national average loss of 40.7%.
If this continues to be my only loss for the spring of 2020, it wasn’t by luck. Good hive nutrition, minimizing queen events and mite monitoring/control was essential in keeping them alive.
