Bat Surveys for Electric Transmission Projects
Electric transmission projects run for miles across the landscape, and building or maintaining them often means clearing forested right-of-way and managing vegetation along long corridors. Where those corridors cross habitat used by federally listed bats, an Endangered Species Act review can follow — and for projects with a federal nexus, that review runs through Section 7 consultation.
Volant EcoServices provides USFWS-protocol bat surveys for electric utilities, transmission developers, and the environmental consultants who support them. Our federally permitted biologists deliver the habitat assessments and presence/probable absence surveys that transmission projects need to stay compliant and on schedule — for the Indiana bat, northern long-eared bat, and tricolored bat across the eastern United States.
Why Transmission Projects Projects Require Bat Surveys
Transmission projects affect bats primarily through habitat disturbance along the right-of-way. Clearing forested corridor for a new line, widening an existing one, or managing vegetation can remove suitable summer roosting habitat. A bat survey requirement is commonly triggered when a project involves:
- Tree clearing and right-of-way vegetation management within suitable bat habitat
- New corridor construction or line rebuilds that disturb forested land
- Projects with a federal nexus — work on federal land, federal permitting or funding, or a Clean Water Act Section 404 permit — which can invoke ESA Section 7 consultation
- State-listed species requirements, which can apply regardless of federal involvement
Long Corridors Are Scoped Differently
Transmission lines are linear projects, and the survey guidelines treat them differently from a single contiguous site — a distinction that drives both cost and schedule on a long corridor.
Under the 2026 USFWS Range-wide Survey Guidelines, survey effort for a linear project is scoped by 1-kilometer section, rather than by the area-based unit used for non-linear projects. And because a transmission line can run across multiple jurisdictions, a long corridor often spans more than one USFWS Field Office. The guidelines specifically cite transmission as an example of a complex project that, because it requires coordination across multiple Field Offices, can take longer to get a study plan approved — on the order of 45 to 60 days.
The practical implication: long transmission corridors benefit most from early survey planning, because both the segment-based level of effort and the multi-jurisdiction coordination take real lead time to scope and approve.
How Volant Supports Transmission Projects
- Habitat assessments. We evaluate the corridor for suitable summer roosting habitat — the assessment that determines whether, and how much, presence/probable absence survey effort is required. Where no suitable habitat is found, no further surveys are recommended.
- Presence/probable absence surveys. Acoustic and mist-net surveys scoped for linear corridors, with all acoustic data manually vetted by federally permitted biologists.
- Linear-corridor survey design. Survey programs structured around the segment-based level of effort and the multi–Field Office coordination that long transmission projects require.
- Section 7 documentation and agency coordination. Survey study plans submitted to and approved by the appropriate USFWS Field Office(s), with defensible reporting to support consultation.
Plan Surveys Early in Project Development
Transmission projects run on long development schedules, but bat surveys can only be conducted during a defined active-season window — and for corridors that cross multiple jurisdictions, the coordination and study-plan approval add further lead time. Identifying survey requirements during routing and design, rather than after a construction schedule is set, is the most reliable way to keep a project compliant and avoid the year-long delay that comes from missing a survey season.
Related: Industries We Serve · Bat Surveys · Bat Acoustic Data Vetting · Threatened & Endangered Species
