MINNEAPOLIS— The Center for Biological Diversity filed a formal notice today of its intent to sue the city of Minnetonka for failing to protect endangered rusty patched bumblebees from a planned mountain-bike course in Lone Lake Park, home to one of the largest populations of the bee in Minnesota.

The rusty patched bumblebee, which is Minnesota’s state bee, has declined by 87% in the past 20 years, and is estimated to be present in only 0.1% of its former range. In awarding Endangered Species Act protection to the bee in 2017, the U.S. Fish and Wildlife Service acknowledged that all of the bee’s remaining populations are important to its survival. In 2018 the Lone Lake Park population represented 13% of the total population in Minnesota and 6% of the remaining populations in North America.

In the past few weeks, several individual rusty patched bumblebees were again found in Lone Lake Park, mere feet from the proposed trail site. Construction of the five-mile mountain-bike course would harm the bumblebees by destroying their homes and causing other disturbances across half of the viable habitat in the 146-acre park.

“The Endangered Species Act is 99% effective at protecting our most imperiled wildlife, but it can only work when its mandates are followed,” said Collette Adkins, a senior attorney at the Center. “Since the city has ignored the concerns of bee experts and residents alike, we have no choice but to take legal action to force officials to protect these important little animals.”

The Endangered Species Act prohibits “incidental take” of the endangered bee without a permit and a “habitat conservation plan” to minimize and mitigate harm. Minnetonka has not developed a plan or applied for a permit for the mountain-bike course, despite the fact that construction is slated to begin next month.

Instead of following the process set by the Endangered Species Act, the city is relying on a cursory and voluntary guidance document from the Fish and Wildlife Service that experts say will not protect the rusty patched bumblebee. Bee advocates hope that today’s notice will convince the city to commit to developing a science-based habitat conservation plan, which is necessary to conserve the rusty patched bumblebee in Lone Lake Park and the region.

“The city of Minnetonka is putting the endangered bee and its habitat at risk without using the channels created by the Endangered Species Act to protect it,” said Heather Holm, a local pollinator conservationist. “As a Minnesotan, I take pride in our state bee, and I want to ensure it gets the protections it needs to keep buzzing for future Minnesotans.”

“We support the Endangered Species Act and hope the city chooses to take the necessary steps to comply with the law,” said Linda Russell of Friends of Lone Lake Park.

As pollinators, rusty patched bumblebees are vital to healthy ecosystems and food security. They were once found widely across the upper Midwest and Northeast, but their numbers have plummeted dramatically since the 1990s, largely because of habitat destruction and threats that are exacerbated by the lack of flowers for them to feed on.

The city has 60 days to respond to the notice. If it does not, advocates can sue under the Endangered Species Act.