05
Oct
American Bumblebee Considered for Endangered Status, But Will “Critical Habitat” Be Defined?
(Beyond Pesticides, October 5, 2021) The U.S. Fish and Wildlife Service (USFWS) will consider listing the American bumblebee (Bombus pensylvanicus) under the Endangered Species Act, according to a notice published in the Federal Register late last month. Earlier this year, the Bombus Pollinator Association of Law Students at Albany Law School and the Center for Biological Diversity petitioned the agency to list the species. USFWS review of the petition indicates that it found “substantial scientific or commercial information indicating that the petitioned actions may be warranted,” and will determine over the next year whether final listing and further protective actions are warranted.
With the American bumblebee experiencing an 89% decline in its population over the last 20 years, scientists and advocates believe it is critical for USFWS to take steps to protect what remains of this iconic species. At one time, the American bumblebee’s range extended from eastern Canada south through the United States into Florida, and as far west as California. Oregon is the only state in the continental US where the species has never been spotted. Declines are particularly pronounced in the northern part of its range, where recent sightings are nil, and assessments for states like New York, Michigan, and West Virginia indicate the species is subsisting at 1% of its historical population levels. While populations are slightly more stable in its southern range, overall abundance is rapidly dropping in states like Arkansas and Georgia, which have experienced 72% and 74% declines, respectively.
Like the Rusty-patched bumblebee, which was recently listed as endangered by USFWS, declines are related to pesticide use, habitat loss, climate change, and disease spread. While bumblebees are generalist foragers, each year a multitude of factors must come together to ensure their population grows. Choosing a spot to nest and overwinter can be fraught with challenges. American bumblebees often nest on the surface, right below ground, or in old logs with mere inches of cover (usually consisting of leaves and twigs). While queen bumblebees do their best to find a quiet, undisturbed site, human activity – ranging from tillage and other agricultural activities to site preparation and construction can destroy overwintering colonies. Mistiming arousal from hibernation with the availability of floral resources due to climate change can likewise stress bumblebees. To respond to climate change, bumblebees must be successful in both moving from away from inhabitable locations and building their population in these new locations – the American bumblebee has so far failed in both accounts. While foraging, diseases can spread between domesticated pollinators and wild bumblebees.
Pesticide use represents one of the most significant threats to bumblebees, and places their entire life cycle at risk. A 2018 study found that commonly used neonicotinoid insecticides begin to kill off bumblebees during their nest building phase, as exposure makes it more difficult for a queen to establish a nest. Then, even if they are successful in setting up a nest, neonicotinoids inhibit bumblebee queens from laying eggs, according to a 2017 study. Exposure to neonicotinoids unsurprisingly results in bumblebee colonies that are much smaller than colonies not exposed to the systemic insecticide, per research published in 2016. And the workers that hatch from these pesticide-exposed queens, that are likely to again be exposed in the field? A 2017 study finds that neonicotinoid exposure decreases pollination frequency and results in fewer social interactions. That is likely because neonicotinoids alter bumblebee feeding behavior, and degrade the effectiveness of bumblebee’s classic “buzz pollination” process.
It is evident that while each of the factors contributing to the decline of the American bumblebee are problematic in their own right, pollinators are exposed to multiple stressors at once. When looking at pesticide exposure, neonicotinoids represent only one class out of thousands of agrichemicals that pollinators could be exposed to. Research published in 2017 determined that fungicides, particularly the chemical chlorothalonil, are playing important roles in bumblebee declines by increasing susceptibility to pathogens like Nosema bombi.
As a result, the most critical aspect of any potential listing under the Endangered Species Act will have to do with what is known as “critical habitat.” This is the area deemed essential to conserving a threatened or endangered species. Such a designation provides the opportunity to establish a range of additional protections within the species’ range. Unfortunately, actions by USFWS do not bode well for recently listed pollinators. For the Rusty-Patched Bumblebee, USFWS determined that declaring critical habitat was not warranted. USFWS claimed that the bumblebee “can find the habitat it needs in a variety of habitats,” and instead has appeared to place priority on mapping potential habitat and public education. While these steps are important, it is critical that meaningful protections be placed around pesticide use and development within the bumblebee’s range. For the monarch butterfly, USFWS actions were even more disturbing. In late 2020, USFWS concluded that monarchs met the criteria for listing, but doing so was precluded due to other higher-priority listing actions. Despite recognizing the dangers that the iconic butterfly faces, USFWS deferred to ongoing state and local efforts to protect the species, merely indicating that the status of the species will be reviewed yearly.
To protect the habitat of endangered species, the U.S. Environmental Protection Agency is required to consult with USFWS and other wildlife agencies when pesticide exposure is likely to affect a listed species. However, the agency regularly fails to perform this role, requiring conservation and environmental organizations to sue in order to prioritize protective actions. Frustrated with this process, in 2019 the Center for Biological Diversity submitted a petition to USFWS and the National Marine Fisheries Services calling on agencies to prohibit pesticide use in all areas deemed critical habitat under the Endangered Species Act.
In light of recent news, U.S. government agencies must prioritize the strongest protections possible for threatened and endangered species. USFWS announced last week that 22 animals and one plant are officially extinct, with causes linked to human-driven habitat destruction, climate change, and other forms of industrial development. Perversely, declaring these species extinct eliminates protections, and any critical habitat that was designated to protect the declining plant or animals. In the future, such a process could result in additional allowances for damaging practices like pesticide use or development. It is not acceptable for taxpayer-funded agencies fail at their purpose, and then weaken protections after that failure.
Take action by urging federal agencies to address mass extinction like the crisis it is by incorporating biodiversity goals into the decision-making process for pesticide approvals. And for more information on the dangers pesticides pose to wildlife and endangered species, see Beyond Pesticides Wildlife program page.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Federal Register, Center for Biological Diversity press release
