Check it out: The impacts of warming winters and falls on the work of honeybees

By Georgine Yorgey (she/her) Associate Director, Center for Sustaining Agriculture & Natural Resources, Washington State University

Honeybees are small but mighty. They produced about 139 million pounds of honey in the US last year, worth more than $350 million.  But even more valuable than that, they pollinate more than 130 types of fruits, nuts, and vegetables, worth more than $15 billion every year. Given how important honeybees are, it is crucial to understand how climate change may impact them and their work.

Climate change has and will change the species distribution of native pollinators (Shi et al., 2021) as conditions change to become better for some species and worse for others. Climate change can also create a mismatch between the timing of forage availability and foraging needs (Goulson et al., 2015; Willmer, 2012), meaning that bees may be active at times when there aren’t enough flowering plants around. And now, some new work from the Pacific Northwest also suggests a pressing need to think about how changing winter temperatures might impact bees. Historically, it was too cold for bees to fly during the winter in the Northwest.  They instead stayed inside their hives, waiting for warmer spring temperatures. However, bees will take flight whenever the temperature is suitable, regardless of whether flowers are in bloom. With warming winters, there will likely be more occasions when temperatures encourage bees to fly. This causes physiological aging in bees, which can lead to an overwintering hive that has older, weaker bees, enhancing the risk of colony failure come spring.

You can read more about this in an article in the WSU Magazine “Honey bees at risk for colony collapse from longer, warmer fall seasons” or in the peer reviewed scientific article, “Warmer autumns and winters could reduce honey bee overwintering survival with potential risks for pollination services” This work shows how climate risks to overwintering bees vary across the Northwest, and explores the potential mitigation strategy of storing bees in cold storage over the winter rather than outside.

References:

Goulson, D., Nicholls, E., Botías, C., & Rotheray, E. L. (2015). Bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Science, 347(6229), 1255957.

Shi, Y., Ren, Z., Zhao, Y., & Wang, H. (2021). Effect of climate change on the distribution and phenology of plants, insect pollinators, and their interactions. Biodiversity Science, 29(4), 495.

Willmer, P. (2012). Ecology: pollinator–plant synchrony tested by climate change. Current Biology, 22(4), R131-R132.