N.H. study finds 14 local bee species on the decline

The ground nesting bee, Andrena vicina, is one of 14 declining wild bee species identified by UNH researchers.Molly Jacobson

Researchers at the University of New Hampshire have found that 14 local bee species are declining dramatically, and they’re pointing the finger at climate change.

All 14 pollinate apple, blueberry, and cranberry crops, according to a study published recently by researchers in Insect and Conservation Diversity, a journal focusing on invertebrate conservation and climate change.

Researchers found that many wild bee species are being forced to move north by increasing temperatures brought by climate change. But some species have found that the plants they usually pollinated were not available in their new territories, and were now competing for scarce food supply, the study said.

“We’re hoping this paper and this kind of coverage will inspire others to have heightened appreciation for what bees do,” said Sandra Rehan, an assistant professor of biological sciences at UNH. “This dramatic decline is of concern here. We can’t speak to the rest of the country, but we’re hoping it will make people pay attention.”

Bees have been on the decline for more than a decade across the globe, and scientists have blamed a range of factors, including insecticides called neonicotinoids, parasites, disease, climate change and lack of a diverse food supply. Bees are critical pollinators, and about a third of the human diet comes from plants that are pollinated by insects.

The latest study examined 119 bee species native to New Hampshire over 125 years, ending in 2016, to track the bees’ habitat preferences.

“Many of these species occur in varied landscapes, climates, and habitats; thus, monitoring changes at regional scales is critical to informing conservation recommendations broadly and focusing future research directions,” the study said.

All 14 of the declining species saw a shift in their habitat elevation and latitude, moving higher, where temperatures are cooler, and to the north, the study said.

Researchers also found that several bee species moved north and weren’t harmed, actually seeing an increase in their populations.

Rehan, who conceived the study, said the effect of climate change on bee movement was much more visible over the lengthy period traced in the study.

“Over 125 years, things that are very subtle on an annual basis are much clearer here,” Rehan said.

Previous research has found that other types of wildlife are changing habitats because of climate change, with many moving northward.

A study published in Science in 2017 found many animals are relocating due to changing conditions in their usual habitats. Some fishermen in northern waters have even found types of fish that once were lucky catches turning into major sources of income.

Rehan said some of the 14 species faced up to a 90 percent decline in population, indicating they could become locally extinct. All hope is not lost, though, she said. Residents can help populations survive by growing out lawns, planting more diverse flowers, and letting weeds grow.

“There are clearly problems with our pollinator community and we have concerns,” she said, but added, “there’s a lot everyday people can do to help wild bees.”