USFWS Issues New Range-Wide Indiana Bat Survey Guidelines

April 24, 2018
Mary Gilmore, Bat Biologist

Mary Gilmore, Bat Biologist at EnviroScience, Inc.

Negative Presence/Absence Bat Surveys Now Valid for 5 Years, Among Other Changes

In April 2018, the U.S. Fish and Wildlife Service (USFWS) issued new survey guidelines for the range-wide Indiana Bat.  One of the biggest changes is that negative presence/absence surveys will now be valid for a minimum of 5 years instead of the previous 2 years. While developers and project managers are pleased with the new rule, other changes increase the level of survey effort depending on the location and type of project.

For example, the acoustic survey level of effort for non-linear projects doubled, while netting survey level of effort for linear projects either increased or decreased depending on region. While those in the Midwest and Ozark-Central Recovery Units saw a decrease in number of net nights required, the Northeast and Appalachian Recovery Units saw a substantial increase.

Other changes include the publishing of a new appendix containing a “pilot” range-wide protocol for conducting survey of potential hibernacula, and new guidance for surveys within 5 miles of a known record.

 The updated guidance was issued just in time for this year’s bat survey season. EnviroScience maintains a full staff of bat biologists to help you navigate these changes. If you or your colleagues have questions, EnviroScience’s permitted bat biologists are here to help. Call us at (800) 940-4025 or email Jamie Willaman at .


The USFWS’s “Range-wide Indiana Bat Survey Guidelines” for the summer is here.

The full guidance is here.