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Bees regulate hive's winter warmth

Terrace beekeeper Rudi Peters says there's a better way to keep hives warm in winter than the traditional way
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The “Broodminder” measures temperature and humidity in Rudi Peters’ beehives this winter. The small box with cord was last year’s temperature only monitor.

A seasoned beekeeper conducting some winter experiments has learned some surprising details about bees.

Rudi Peters put a thermometer in some of his hives last year in winter to see how well the bees regulated their temperature and this year has switched to a different device that is easier to use and also measures humidity in the hives.

“It should be self-evident that the hive best able to maintain the internal environment should survive the best,” he said.

When he began beekeeping seven or eight years ago, beekeepers told him to flip over the top of the hive in the winter to let out the humidity – flipping the top makes an opening along the side near the top.

Peters asked why it was done and wasn’t given an answer, just  that it’s how it’s always been done.

“If you know the ‘why’, then the ‘how’ takes care of itself,” he said.

But he figured that flipping the lid would also let out the heat, which means the bees will have to expend energy to warm the hive.

During winter, there are about 30,000 bees that pack into a volleyball-sized ball at the bottom of a hive to keep warm.

Peters said they will move around in the ball like the March of the Penguins, moving from the outside to the inside and back out again so everyone shares the temperature equally.

Humidity in the hive will condense but only when it comes up against cold air, said Peters.

This is more likely to happen when the top has been flipped, he said.

So he decided to not flip the lid in the winter and to run some experiments on the temperature and now the humidity in the hive.

In addition to not flipping the lid for the last two years, Peters took two rows of bubble wrap, put them between two aluminum foil mylar sheets and laid it on top of the hive just under the roof.

The mylar redirects the heat back into the hive instead of it getting lost out the top and with the addition of an R20 insulation pillow on top of the mylar, there’s zero heat loss, he said.

Below the pillow and mylar sheets, he places a sensor, which looks like a ruler and sends information via bluetooth to his iPhone.

Peters set up an empty hive for a control.

The temperature difference on the empty hive was 27 degrees at its warmest and below zero at its coldest.

Bees can’t survive more than a 10 degree difference from warmest to coldest, said Peters.

With the roof not flipped, he has found that the outside temperature can drop to -20 degrees and the bees in his hives will still be able to maintain the temperature inside the hive at pretty close to 10 degrees.

Taking one day’s data as an example, he found in the hive with bees that temperature remained very consistent and the humidity was around 75 per cent.

The empty hive on the same day had humidity of 90 per cent, he said.

“Last year, I was quite shocked (about their temperature control),” he said, adding that it doesn’t make sense to let out the heat when it’s not necessary as the bees control it just fine.

“Humidity surprised me too. I didn’t expect them to control it as much as they do,” he said.

Peters has found a few flaws with the sensors and sent one to an engineer friend who is going to see if he can improve it.

Coming up in March, Peters wants to present his findings at a beekeeping convention in Kamloops and write it up as a technical paper for a journal.

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A few fun facts about bees from Peters:

• A strong hive can put out the heat of 40 100-watt light bulbs.

• People say bees are domesticated but they’re not, they’re wild animals.

“You can’t make them do anything,” said Peters. “You can encourage them to work on your own schedule.”

• Bees think collectively and not individually (similar to the Borg in the newer Star Trek TV series, said Peters).

• Bees can do things that make humans look very simplistic.

For example, their capacity to navigate is far superior.

We need a super computer to keep ourselves on the correct path, but bees navigate “on the fly” literally.

They use the sun for navigation but the sun isn’t stationary so they triangulate it with certain hairs on their body and have extra eyes that can determine windspeed so they can compensate for strong winds.

• Good strong bees can fill a hive with honey in one or two weeks.

• Swarms don’t happen because bees want to go out and sting people like Hollywood movies would have us believe; rather, swarms are a part of reproduction, said Peters. A new queen will be made and the former queen will take about one-third of the bees with her.

They will fly to a good place to hang out, such as a tree, and stay there together while several scouts go out to find a good location to make a new hive.