Why Warm Winters Like We’re Having Are A Problem For Honey Bees

When it’s cold, honey bees cluster together in their hives feeding on the honey they saved to eat through the winter, vibrating to generate warmth.

“The bees are inside keeping their brood warm,” said Linda Tillman, a master beekeeper and the president of the Georgia Beekeepers Association.

She was bundled up on a cool winter day next to a beehive in a community garden in Atlanta’s Morningside neighborhood. Cool enough, that the colony was quiet, just how Tillman would hope for it to be this time of year.

The problems arise when the temperature is a little warmer, around 50 degrees, which has happened a lot this winter. When it gets that warm, the bees will start coming out of the hive, to clean up and to look for pollen and nectar.

“If it is a really warm day, they start looking for the possibility that spring is actually here,” Tillman said. “And at this time of the year, there’s no nectar. So they fuel themselves with the honey they have stored in the hive, and that uses up their stores.”

If this happens a lot, the bees might eat all the honey they’d saved for the winter, and there’s a risk of starvation, said Jennifer Berry, research coordinator at the University of Georgia honey bee lab.

“We do see higher starvation rates during warmer winters,” she said. “And if the beekeepers are not paying attention, then we do lose the colonies.”

Beekeepers can feed their honey bees sugar water to get them to the spring. Bobby Chaisson, who keeps about 150 hives around Georgia and also does bee removal, said that means, for now, making adjustments for warm winters are mostly just annoying.

“But I think as it trends over the next 15, 20 years if it stays in this type of trend, where it’s getting warmer through the winters, it’s going to become a significant problem,” he said.

Cold Storage

There’s also an age issue.

Flying around wears bees out. It’s kind of like cars; lower mileage means a fresher bee.

“When bees fly, physiologically they’re aging,” said Gloria DeGrandi-Hoffman, an entomologist specializing in honey bees at the U.S. Department of Agriculture.

In the spring, it’s better for the colony to have fresh, energetic new bees, ready to get out there and forage, she said. Not old clunkers that clocked in time flying because it was too warm to settle in.

“The population being made of older individuals, they begin to decline and can cause colonies to either die over the winter or early in the spring,” she said.

Winter starting later can also aggravate the spread of parasitic mites, which can weaken and kill bee colonies, DeGrandi-Hoffman said.

Warmer falls and winters are enough of an issue that DeGrandi-Hoffman now studies a possible solution: keeping bees in cold storage. She works with commercial beekeepers who truck their bees from farm to farm, pollinating things like almonds. In one of her studies, hives were kept in cold storage in Idaho until the spring.

“You’re sort of simulating the way it was decades ago where you had October come around, and it started to get cold, and by November, the bees really weren’t flying anymore,” she said. “I think every year, more colonies are going into cold storage.”

In Atlanta, beekeeper Linda Tillman makes her own adjustments to the changing climate.

“I’m always thinking about the winter coming,” she said.

She held back on harvesting honey last year, to make sure her bees have enough to get them through this weirdly warm season.