Western honey bee colonies at risk of collapse, study finds – The Mercury News

Conrad Swanson | (TNS)The Seattle Times

SEATTLE — One of nature’s most important keystone species is dying on the job.

Colonies of honey bees – essential pollinators for a wide variety of plants and cash crops – are at risk of collapse due to climate change, according to a recent study by scientists at Washington State University and from the United States Department of Agriculture.

Long, warmer fall months in the Pacific Northwest encourage bees to move out of their colonies when they should be resting, said Gloria DeGrandi-Hoffman, research manager at the Carl Hayden Bee Research Center in the USDA in Arizona.

“When it’s hot, they fly, and when they fly, they age physiologically,” said DeGrandi-Hoffman, who is also one of the study’s authors. “It’s very taxing to fly.”

In the spring, bees that should emerge young and rested are instead old and infirm, she said. They are too old to care for younger generations of bees, who in turn cannot care for subsequent generations.

When colonies drop below a certain threshold (about 5,000 bees), several things start to go wrong and the population soars, said Brandon Hopkins, another author and director of the Beekeeping Program and Lab. WSU. The bees will no longer be able to keep warm, the nursing bees will no longer be able to feed the developing brood, and there will not be enough bees to forage for food.

“Everything is falling apart,” Hopkins said. “The whole system crashes. »

All because of a temperature increase of a few degrees.

The study modeled many different climate scenarios for decades to come, said Kirti Rajagopalan, another author and an assistant professor in WSU’s department of biological systems engineering. The severity of the warming trend in the Pacific Northwest depends on whether humans reduce greenhouse gas emissions and, if so, how much.

The warmest fall and winter months do not occur every year and Earth will continue to experience its natural variability, but climate change is pushing each end of the spectrum toward more extremes than before.

Not only did global temperatures mark the hottest year on record in 2023, but regional temperatures also regularly reached record highs.

By 2050, warm fall and winter temperatures could reach 4 or 5 degrees above normal, Rajagopalan said.

“Two degrees might not make a big difference at the beach,” Hopkins said. “But it can make the difference between bees that fly and bees that don’t.”

The difference between a sustainable bee colony and its collapse.

Some years, between 40 and 60 percent of bee colonies collapse nationwide, DeGrandi-Hoffman said. The consequences will become more and more apparent.

Not only can the study’s findings apply to bees outside of the Pacific Northwest, but other pollinators are also suffering, DeGrandi-Hoffman said.

“They really are the glue of our ecosystems,” she said. “And you never notice the glue, until it stops working.”

With bees in particular, this glue (pollination) produces about a third of our food as humans, Hopkins said.

“Typically the most nutritious and delicious foods we have,” he said. “Fruits and vegetables as well as a large part of nuts are produced by bees. »

There is also a beef and dairy component, Hopkins added. Bees pollinate forage crops like alfalfa, which feed cows.

Don’t forget the honey either.

Eric Olson witnessed this widespread pollination. He also witnessed the collapses.

For 40 years, Olson trucked his 18,000 bee colonies between California and Washington, moving between farms and orchards where their job was to pollinate everything from almonds to fruit trees to blueberries, blackberries, cranberries, carrots, radishes, onions, canola and alfalfa.

For years, Olson said, “seven days a week, at 2 a.m., I was somewhere in my big truck, hauling bees.”

Bee populations declined toward the end of Olson’s career, and during his last winter in business he lost nearly two-thirds of his hives.

He fondly refers to newly hatched bees as “little fuzzies,” who are imperiled by unseasonably warm weather during periods of low food availability.

“The little fluffies were hatching when they normally would, but since they were outside and it was warm enough to fly, they were coming out but there was nothing for them,” Olson said.

“They have exhausted their lives,” he said.

Olson sold his business in 2016 and the decline continued until a complete collapse, he said.

“Last year was the first year since 1980 that there was no pollination by Olson’s bees in the Yakima Valley,” he said.

Although bee populations are suffering across the country, they are not all collapsing at the same time or for the same reasons. A survey by the nonprofit Bee Informed showed that beekeepers recorded their second highest loss rate on record last year. At the same time, the population of other domesticated colonies in Texas has exploded in recent years, the Washington Post reported.

The problems a given hive faces depend on many factors, including climate, location, and whether it is a domestic colony or not.

Besides warming temperatures, Olson said bees are also suffering from a lack of food and widespread viruses.

Fortunately, experts agree, there are solutions.

Beekeepers can rely on cold atmosphere storage to replace the cold climates that typically trigger a dormant period in hives, Olson said.

And some farmers use huge black or white tarps to heat or cool the soils where wild bees live, Hopkins said.

The Washington state legislature passed a measure this year requiring projects that include landscaping to make at least 25 percent of the area a “pollinator habitat” using native plants. Gov. Jay Inslee signed the measure Thursday.

However, what will prevent the greatest warming is for humans to reduce their greenhouse gas emissions and work to reverse the worst effects of climate change, Rajagopalan said.


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