Bees of all shapes and sizes form a gently humming backdrop to many landscapes, catching people’s eyes as they zip along. Beyond their charms, they play an indispensable role in many ecosystems. Nearly 90% of flowering plant species, including 75% of agricultural crops, benefit from animal pollination. The United States alone grows more than 100 crops that either need or benefit from bee pollination, and the economic value of these native pollinators is estimated at $3 billion per year.
Bees are intimately tied to flowers by their use of pollen as a protein source, making them the most important pollinator taxon in many regions. Ongoing threats to managed, non-native Western Honey Bees (Apis mellifera) have raised public awareness of bees’ importance to human well-being, and pointed to the possible decline of some of the approximately 4,000 native U.S. bee species. (See this blog post for a nuanced discussion of honey bees and their interactions with native species.)
Before this survey, we estimated that over 300 species of wild bees inhabited Vermont. But no one had ever conducted a full survey of the State’s bees. Without a complete checklist of species, it was impossible to even begin the process of determining exactly which of Vermont’s wild bee species were thriving or declining, new to the state or lost.
Starting in 2019, volunteers and project staff intensively surveyed Chittenden County, which includes Burlington, amassing over 7,000 specimens, including dozens of species never before recorded in Vermont. We also catalogued and identified historic bee specimens in the major insect collections in Vermont and beyond. We then expanded beyond Chittenden to survey every county and all biophysical regions in the state.
The survey’s main aims were to:
- Obtain a baseline of bee species and their distribution at the beginning of this century for comparison to historic and future data.
- Curate and share all historic and current bee records from Vermont in an open data portal via the Vermont Atlas of Life (VAL) and the Global Biodiversity Information Facility (GBIF) .
- Assess the conservation status and needs of Vermont bee species.
- Identify habitats of statewide and regional importance.
- Educate and involve more people in the discovery and protection of Vermont’s natural heritage.
Where It Started
The Vermont Bumble Bee Atlas
Northern Amber Bumble Bee nectaring on Red Clover. / © K.P. McFarland
The Vermont Wild Bee Survey is closely modeled after our recently completed Vermont Butterfly Survey and the Vermont Bumble Bee Atlas .
We completed the Vermont Bumble Bee Atlas , a project of VCE’s Vermont Atlas of Life , from 2012 to 2014 with help from over 50 trained community scientists. Together, we surveyed across the entire state, amassing a database exceeding 10,000 bumble bee records from all of Vermont’s counties and biophysical regions, and 81% of the state’s 255 municipalities. To compare current bumble bee diversity and distribution in Vermont to historic records, we assembled a database of nearly 2,000 bumble bee records, some from as early as 1915, from 13 public and private insect collections. The results provided sobering news about the status of Vermont’s 17 bumble bee species, and led to the listing of four species as Threatened or Endangered in Vermont, one federally Endangered, and added nine species to the 2015 Wildlife Action Plan as Species of Greatest Conservation Need (SGCN).
This effort spawned a passionate network of volunteer community scientists, a valuable baseline, and a conservation concept for some pollinators in the state.
Learn more about the results from the Vermont Bumble Bee Atlas.
Silky-striped Sweat Bee (Agapostemon sericeus) in a pollinator garden. © Kent McFarland
As exciting as this work on a charismatic mini-fauna might be, bumble bees may not be representative of the approximately 37 other bee genera in Vermont. Unlike bumble bees, most of Vermont’s 350+ bee species are small, solitary, and poorly understood.
For example, although roughly 20% of these species are pollen specialists—obtaining pollen from a limited number of flower species or genera— some studies show that many wild bee species provide important ecosystem services. In one instance, scientists at UVM associated with this atlas demonstrated that more than 90 species of wild bees visit Highbush Blueberry flowers on Vermont farms, contributing thousands of dollars of value to the state’s agricultural economy. And nearby in New York, Cornell scientists recently found that native bee diversity is key to better apple production. Yet there is still a lot to learn about which species are in Vermont and how they fit into the pollination networks of the state, work that will have to continue long after this atlas.
Conservation Ranks & Priorities
Vermont is one of a few states with a complete conservation ranking of its entire bee fauna.
A critical step in setting priorities for biodiversity conservation is an assessment of extinction risk. This requires detailed knowledge of the distribution, population size and trends, and critical threats for each species. The NatureServe Conservation Rank Calculator enables conservation biologists to translate this knowledge into three categories of information: rarity, threats and trends. The tool uses these data to determine an overall conservation status rank by automatically applying specific rules. These results are then reviewed by experts and in some cases adjusted based on further information.
We have assigned state conservation rank s (S-ranks) to most of the native bee species in Vermont. Ten species that had no records after the year 2000 were assigned an SH (Historical) or SX (Extirpated). Over 30% of Vermont’s extant native bee species are now ranked as critically imperiled or imperiled. Many critically imperiled species are known from just a few records, often from a single location, and with no direct information about population trends. Many of these species may be naturally rare in Vermont, making their populations susceptible to environmental perturbations. On the opposite spectrum, nearly 23% of native bee species are apparently secure or secure. More occurrence records and threat assessments are needed to improve and clarify these some ranks.
We identified 43 bee species that are in urgent need of conservation efforts and have been assigned as Species of Greatest Conservation Need (SGCN) in the upcoming 2025 Vermont Wildlife Action Plan . Additionally, our knowledge of Vermont bees was incorporated into the Northeast Association of Fish & Wildlife Agencies recent update to the list of Regional Species of Greatest Conservation Need. The list now includes 19 bee species that have been recorded in Vermont.
