Tuesday, January 12, 2010

Do Honey Bees Hibernate?

As I was walking from my house to my car on my way to work this morning, I noticed a honey bee lying on my sidewalk. Two days previous, I had seen a dead honey bee on the window sill right above this spot on the sidewalk, so I checked to see if maybe this bee had fallen from its perch. It had not. The bee on the window sill and the bee on the sidewalk were both honey bees, and both had met their demise near my front door.

This got me to thinking. Where do honey bees go in the winter time? Why had these bees unfortunately strayed too far from warmth and safety and perished in front of my home?

It may come as no surprise that honey bees spend the cold winter months in their hives. But what they don't do is hibernate. Instead the bees form what is called a "winter cluster." The worker bees huddle and swarm around the queen bee, who is at the center of the cluster, and shiver in order to keep the center warm. The worker bees move in and out of this cluster so that no bee gets too cold in the outer layers of the cluster. I suppose this is similar to a March of the Penguins style when the males watching the eggs during the coldest months of antarctic winter form a rotating huddle and move in and out of the huddle to keep each other warm.

Studies of over-wintering honey bees have shown that the hive consumes about 30 pounds of stored honey during the winter months. The honey that bees work so vigorously to store during the spring, summer, and fall makes the hive's survival possible. Heat energy is produced by the oxidation of the stored honey and this heat is circulated throughout the winter cluster by the wing-fanning of worker bees. The center of the cluster hovers around 80 degrees Fahrenheit, and the outer edge stays around 46-48 degrees Fahrenheit. The colder it gets outside, the tight the cluster becomes to keep everyone warm.

So why were there two dead honey bees near my front porch this morning? Honey bees stop flying from the hive when the temperature reaches around 50 degrees Fahrenheit. At this time the temperature gets too cold for the bees to be able venture far from the hive without risking death of exposure. There is also not much reason for the bees to leave the hive because there are no flowers in bloom from which to collect nectar. But the bees still need to be able to eliminate their bodily waste, as bees are very tidy creatures. On warmer days, the bees will venture out of the hive to do this. These flights are very short and the bees generally do not venture far because they can't make it back to the hive if they get too cold.

This must be what happened to my resident honey bees. It did get rather warm on Sunday afternoon and yesterday afternoon and the bees were probably taking advantage of the few hours of radiant sunlight. There must be a hive somewhere near my house, but a bit too far for the bees to make it back safely. Hopefully these two will be the last that make it this far before heading back home to the life-sustaining warmth of their hive.


Dave's Garden - text and hive diagram


paul said...

My 7-year-old son has been up for several hours at night a couple of times a week in the last month because he's been having nightmares. Last night he had a nightmare about bees, and we had to take all the blankets off the bed and turn over every pillow to show him that there were no bees in his bed.

Tonight at bedtime he started getting scared, so we decided to look up some information about what bees are doing during the winter, and found this blog. He read it and laughed and smiled, and went to bed.

It's a very interesting post by itself, but now you can know that it also helped a little boy in Seattle (and his parents) sleep well. Thanks!

Nicole said...

Hi Paul - that is so great! I am so glad that my post helped your son (and you too!) with his fears. Honey bees are very interesting and amazing insects and I enjoyed composing this post and learning more about them very much - indeed one of my favorites!

Thank you very much for taking the time to tell me your story and for the positive feedback! Cheers!

Jennifer said...

Thanks very much for this informative post! We just saw a honeybee land on our windowsill and wiggle around, so I and my children decided to find out why we're seeing a honeybee when it's 45 degrees outside. Your post is the first one we read, and now we're wondering where the hive could be! How far away from the hive do the bees venture in the winter -- yards or miles? Thanks again!

Anonymous said...

Most worker bees die of exposure following wing loss. Yes, bees fly till a wing falls off, then crash land. Being alone, they die of exposure.

Anonymous said...

A friend of mine found a huddled mass of bees at her neighbors house in (Sierra Vista, AZ) while walking her dog, was wondering if you could give her or me some advice on what to do.

I'm attempting to attach a link to a pic of the bees, hope it works!


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