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iSeeChange: Beekeepers worry about impact of warm December weather

Eli Chen/Delaware Public Media

Delawareans likely remember how harsh last winter was and having to deal with many weeks of cold temperatures. Among those most concerned about very cold weather are beekeepers -- because honey bees spend their winters clustered in their hives, trying to keep warm. When harsh winter conditions force honeybees to stay in their hives longer, they’re more likely to starve and infections could spread as the bees become weak from the cold.

But now, beekeepers are worried about the effect the warm temperatures in December will have on their hives. In our latest feature for iSeeChange, Delaware Public Media’s Eli Chen explains why.

I was standing about five feet from a colony of bees who all live in a tall white box in a backyard in Lewes. And what I saw a lot of activity -- bees perched either on a ledge of the white box or flying around a small opening. They looked like kids who’ve been let out for recess.

“Well, it looks like the bees are in flight school, which means they’re oriented to where their hive is in relation to the sun so they can find their way back to the hive once they’re out foraging,” said the bees' owner Theresa McManaman.

She started beekeeping just last spring. And she remembers seeing this “flight school” activity in June. But I should note that at the time of this recording -- it was December. Christmas Day, to be exact. And Theresa found it very unusual.


“No, this would not happen right now. They should be a cluster inside the hive, keeping the hive warm in what should be very cold weather. But they’re out having fun instead,” said McManaman.

And the reason they were out and about is because of the unseasonably warm weather that day. In Sussex County, Delaware, it was sunny, with highs in the lower 70s. On the way to Theresa’s house that day, I saw a couple of joggers outside in t-shirts.

But the way the bees were behaving has Theresa concerned that they might struggle this winter -- especially since all the flowering plants they’d forage from have long gone to bed for the winter. And she’s not the only beekeeper who feels this way. Ken Outten is the president of the Delaware Beekeepers Association.

“One of the concerns is how are they using their honey reserves," said Outten. "And a lot of beekeepers will be concerned if they will have enough reserves to last them all winter”

That’s because during the winter, honey bees will huddle together in their hive, trying to conserve their energy. And they need to rely on a supply of honey to get them through the season.

Outten has a more elaborate operation than Theresa McManaman’s. He has about 70 hives, which he uses to pollinate his strawberries. He also breeds queens to sell to other beekeepers. And he’s been doing this for at least 12 years. The harsh winter last year was brutal for his bees.


“Last winter was my worst winter. And I had nearly a 50 percent loss. Years prior, the losses didn’t run so high," said Outten. "But last year was a very bad year.”

And this winter, in some ways, is just as challenging. Because his hives also were active on the warm December days, they’re expending energy that they’re not able to replace. So he’s trying his best to make sure his bees don’t starve.

“It’s this great big, I don’t want to say game, but it’s a thing we have to manage as beekeepers. Knowing the answer is not always easy,” said Outten.

Dennis vanEngelsdorp runs University of Maryland’s bee lab -- and he says the hive collectively is like one warm-blooded superorganism. And it has to maintain enough heat to make it through the cold season.

But when winter starts off as warm as it did in December, the bees are likely to deplete their honey reserves faster. vanEngelsdorp says that the compact ball bees form inside the hive expands when it gets warmer.

“So when it’s really cold they’re like a baseball and when it’s warm, it’s like a basketball. When it’s a basketball more heat gets released because the surface area is greater, so they need to eat more honey to keep it at the same temperature,” vanEngelsdorp said.

vanEngelsdorp has actually had to feed his research hives in Maryland every week to sustain the colonies. Outten has been feeding his own bees as well.

“Well, most of the time it’s table sugar or sucrose. They can also take in fondant, hard candy, and sometimes they can process granulated sugar in the right conditions, but it’s very tricky,”  Outten said.

vanEngelsdorp says that depleting honey reserves isn’t the only thing that beekeepers should worry about. When fall becomes winter, honey bees usually will stop rearing young. But because of the late fall weather it’s likely the bees have instead continued to do so.


With the warm weather, brood has been produced for a longer period for the course of the year and it starts up earlier and that means that the real enemy number one, the varroa mites," said vanEngelsdorp

Varroa mites are parasites that feed on adult worker bees and developing brood. They’re also thought to be one of the potential culprits of colony collapse disorder -- a global phenomenon to explain the mass disappearance of pollinators.

In the winter, varroa mite populations decline because there’s no honey bee brood to feed on. However, if bees continue to rear young due to warmer weather--

“We think varroa mite levels will be really high in the spring and so that usually an indicator that we’ll have heavy losses,” said vanEngelsdorp.

So he stresses that all beekeepers -- especially backyard beekeepers -- develop a varroa mite management plan. Almost 60 percent of backyard beekeepers don’t have one, according to a study conducted by the Bee Informed Partnership.

When it comes to treating for varroa mites, vanEngelsdorp recommends that beekeepers use formic acid, followed by ursolic acid. Thymol-based products can also keep the parasites at bay.

But despite all of the protective measures that beekeepers can take, this past month was an odd start to the season. And vanEngelsdorp believes the warm weather may have confused the bees in a way that will hurt them, especially now that temperatures have dropped to normal wintertime levels.

“I think with the warm sporadic weather they might start to rear brood and oh spring’s on the way, where there’s this cold that still going to be coming. If they rear a lot of brood then it gets cold like it did, they’ll try to keep the brood warm and not move on to the honey. So I imagine it will be a bad winter for mortality on the East Coast,” said vanEngelsdorp.

Honey bees, like many insects, have evolved to put up with shifting climates -- that’s what’s allowed them to live from the equator to as far up north as Alaska. But wherever they live, they’ve adapted to that area’s seasonal patterns. So when things like temperature don’t change like they’re supposed here in the Mid-Atlantic, it appears that could lead to some unwanted consequences -- which beekeepers will likely see once spring comes back.

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