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A November 4 press release announced that a two-decade decline in the American bumblebee population had prompted the U.S. Fish and Wildlife Service to spend the next year evaluating whether to protect the species by placing it on the Endangered Species Act.
According to the Center for Biological Diversity and Bombus Pollinators Association of Law Students, the American bumblebee has disappeared from eight states. These two groups included this information in a petition to the U.S. Fish and Wildlife Service asking them to conduct a study of the American bumblebee.
Elaine Evans, Ph.D., a University of Minnesota Extension Educator and bee researcher, commented on the demise of the bumblebee. In addition, she answered a number of questions for the Cook County News-Herald.
“The press release is about one species of bumblebee, called the American bumblebee. Globally about one in three bumblebee species are in decline. Some species are doing fine or are even expanding their populations,” Evans said.
“To date, in most areas, other bumblebee species fill the niches left by the declining bumblebees, so we have not seen much of an impact, as plants are still getting pollinated.
“I am not convinced that the American bumblebee has disappeared from the eight states as is claimed in the petition. The states are Oregon, Idaho, Wyoming, Maine, New Hampshire, North Dakota, Rhode Island, and Vermont. Just last night (November 3), I spoke with a researcher in Wyoming who still sees the American bumblebee there, so the information in the petition appears to be incomplete.
“However, there is good evidence that the bee has declined 51 percent on average across its range.
“Here in Minnesota, we still find them, but there are many areas where they have declined. However, in southwestern Minnesota, they remain common.”
Evans added the “American bumblebee populations have been dwindling over the last 20 years, with fewer numbers seen and a reduction in their range. While the cause of their decline is not known, pathogens and climate change may play a role.
“The American bumblebee has been shown to have higher pathogen loads than other bumblebee species that are not in decline. They have not been found in the northern parts of their former range. With climate change, northern areas in North America experience wider temperature fluctuations than areas farther south. This wider temperature fluctuation could cause stress that exceeds what American bumblebees can tolerate.”
How can you help bumblebees? Evans advises going to the University of Minnesota webpage for advice on bees. Below are some tips from that page.
“You can help bumblebees by providing them with food and shelter. Bumblebees get all their food from flowers. They visit a wide range of flowers. Their favorites include gooseberry (Ribes), bee balm (Monarda fistulosa), anise hyssop (Agastache foeniculum), asters and many more. To provide shelter, the best option to encourage bumblebee nesting in gardens is to create habitat, rather than putting in “houses.” The basics of what they need are a sheltered space with insulating material. This can be a compost pile, piles of dried grass at the base of native grasses, or a raised bed that has sticks and logs at the base (look up hugelkultur to learn more).
“If you are able to leave leaves on the ground and add some logs to leave to rot, they seem to be attracted to those. Some people do make houses that bumblebees can use for nesting. However, people who put outhouses have a 0-10% success rate, so, it may not be worth the effort compared to habitat creation. If you would like to try, the Bumble Bee Conservation Trust has created a guide: Making a bumblebee nest.
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