Navigating Regulatory Requirements to Limit Impacts to Clients and Essential Species

Posted April 17, 2024

Proposed Endangered Species Listing for Tricolored Bat (Perimyotis subflavus)

CHA’s Ecological Team often works on projects that involve habitat restoration and environmental permitting in areas where wildlife will be impacted. CHA’s scientists are committed to helping protect essential species, such as bats, in our ecosystem and to aiding clients in navigating the regulatory statutes that could impact their projects. The goal of these efforts is to incorporate best management practices to help limit impacts to clients and the essential species.

According to the United States Fish and Wildlife Service (USFWS), “Bats play an essential role in pest control, pollinating plants, and dispersing seeds. Recent studies estimate that bats eat enough pests to save more than $1 billion per year in crop damage and pesticide costs in the United States corn industry alone.” As bats continue to decline in population, their impact will become more troublesome to our ecosystem. One of the most important ways we can all help bat populations, including the northern long-eared bat, is to prevent disturbing bat habitats including dead and dying trees, which are commonly utilized as roosting sites.

The NYS Department of Environmental Conservation (NYSDEC) has imposed tree cutting restrictions during the spring and summer months when bats are roosting in trees. These restrictions allow for and promote best management practices of clearing and cutting trees from November 1 to March 31 when bats are inactive and are within their hibernacula (NYSDEC, 2020). The NYSDEC also restricts cutting of any trees inside the ¼ mile buffer around any hibernaculum (NYSDEC, 2020). Planning for projects in areas where these restrictions limit site clearing is an important element in planning site development work.

The tricolored bat (Perimyotis subflavus) is currently undergoing review by the USFWS as a candidate species to be listed as endangered under the Endangered Species Act. The tricolored bat is known to be found in 39 states in the eastern and southcentral United States, four Canadian provinces (Ontario, Quebec, New Brunswick, Nova Scotia), and is also known to live in Guatemala, Honduras, Belize, Nicaragua, and Mexico (USFWS 2022). The tricolored bat is a relatively small insectivorous bat species that is differentiated by its unique tricolored fur, which often looks yellowish to nearly orange (USFWS n.d.).

Like many bat species, during the winter months, the tricolored bat is often found in caves and abandoned mines. However, in the southern portions of their range, where caves can be sparse, they are often found roosting in road-associated culverts, where they exhibit shorter winter torpor and forage during warmer nights (USFWS n.d.). Through the spring, summer and fall months, tricolored bats can be found in forested habitats where they utilize various trees for roosting, primarily among leaves of living or recently dead deciduous hardwood tree species. They have also been found to utilize Spanish moss (Tillandsia usneoides), pine trees (Pinus spp.), and occasionally roost within build structures (i.e., barns, attics, etc.).

The tricolored bat was previously known as the eastern pipistrelle (Pipistrellus subflavus) (NYNHP 2024). The taxonomy change came in 2003. Within the eastern portion of the species range, populations have considerably declined due to the fungal disease white-nose syndrome (Pseudogymnoascus destructans, WNS) (Cable & Willcox, 2024). These bats face extinction from the range wide impacts of WNS, a disease affecting cave-dwelling bats across the continent (USFWS n.d.). The primary factors influencing the tricolored bats' viability, which have led to the current proposed listing status, include the following: WNS, wind-related mortality, effects from climate change, and habitat loss (USFWS 2021).

WNS is a fungus affecting cave-dwelling bat species across North America. Research has shown that the tricolored bat faces endangerment with potential extinction in certain localities of its range due to range-wide impacts from WNS. This disease has been reported to threaten the species in over half its geographical range (59%) and has resulted in the decline of 93% of the population (Cheng et al. 2021).

The USFWS mentions that WNS is the primary driver that has led to their decision to review the species for listing. Additionally, wind energy mortality is also proving to be a consequential driver of tricolored bats' viability, especially considering the steep declines stemming from WNS impacts (USFWS 2021). Bat fatalities continue to be documented at wind power installations across North America and Europe. There are several climatic factors that may impact bats, such as changes in hibernation, mortality from extreme drought, cold, excessive rainfall, cyclonic storms, loss of roosts from sea level rise, and human-induced impacts (i.e., wind turbines, forest clearing, etc.). These variables influence the tricolored bats’ resource needs, such as suitable roosting habitat, foraging habitat, and prey availability (USFWS 2021). Forests are a primary component for roosting, foraging, and commuting between habitats (USFWS 2021). Wetlands and water bodies are equally important for foraging and drinking water sources. The loss of these habitats directly affects the survival and reproduction success of the species (USFWS 2021).

Understanding that the tricolored bat proposed Endangered Species listing has the potential to influence all types of project development, USFWS has developed and is continuing to fine-tune some consultation tools to help the industry comply with the new regulations. USFWS has replaced the 4(d) Rule with a “determination key” to permit developers to receive automatic verification of compliance for certain projects.

The USFWS announced on March 12, 2024, that there has been an extension to the interim tools (via the USFWS Information for Planning and Consultation [IPaC] website) used for effects determinations for northern long-eared bat (Myotis septentrionalis, NLEB). The interim wind guidance, interim habitat modification guidance, and interim Section 7 consultation framework were originally scheduled to be in place until April 1, 2024. USFWS has since extended the interim NLEB tools and guidance for use until final tools are issued, tentatively scheduled for the summer of 2024. The new tools proposed for implementation this summer will also apply to the tricolored bat when and if its proposed endangered species listing is confirmed.

With expertise in bat emergence, habitat assessments and tree surveys, our team is well-equipped to assist clients in utilizing USFWS determination keys. Whether evaluating existing conditions or aiding in compliance measures, our team delivers a thorough understanding of bat habitats and contributes to informed decision-making in ecological assessments. If your project involves potential ecological constraints, particularly related to bats, please connect with CHA’s Ecological Team for regulatory support and expertise to navigate the ecological considerations of your site in your project planning and implementation.

For more information on the tricolored bat, visit the U.S. Fish and Wildlife Service at or the New York State Natural Heritage Program