North American Bat Monitoring Program (NABat)

Science Center Objects

North American bats face unprecedented threats including habitat loss and fragmentation, white-nose syndrome, wind energy development, and climate change. However, it is difficult to evaluate the impacts of these threats due to a lack of basic information about the distribution and abundance of bats across the continent. Although bat monitoring has long been conducted in individual areas and for individual projects, until now, there has been no statistically robust and standardized monitoring program to assess the status and trends of bat populations across North America. The NABat program provides information to broad constituency garnered from a continental-scale, long-term program, and allows them to better document changes in bat populations, estimate extinction risk, set conservation priorities and evaluate the effectiveness of conservation actions.

Image: Side View of Insect-Eating Spotted Bat (Euderma maculatum) in New Mexico

This spotted bat, native to western North America, is a hibernating insect-eating bat that may be at risk as the disease white-nose syndrome moves westward.Public domain

What is NABat?

  • The North American Bat Monitoring Program (NABat) is an international interagency program designed to monitor bat distributions and abundances on public and private lands, and provide trend data at the state, provincial, tribal, regional (e.g., Landscape Conservation Cooperatives), and range-wide scales.
  • The goal of NABat is to provide natural resource managers with information required to manage bat populations effectively, detect early warning signs of population decline, and estimate extinction risk.
  • NABat will allow state, provincial, and federal agencies to better prioritize limited resources and engage in cross-agency collaboration. Over time, NABat will involve the public in monitoring and conservation activities.

Scope of NABat

Currently, NABat concentrates on the 47 species of bats found in Canada and the U.S. Over time, NABat will integrate with an existing monitoring program in Mexico. 

Methods and Approaches Used in NABat

Southeastern Bat with P. destructans Fungus

This southeastern bat (Myotis austroriparius) from Alabama shows signs of infection from the Pseudogymnoascus destructans fungus that causes white-nose syndrome in bats. (Credit: Dottie Brown, Ecological Solutions, Inc.. Ecological Solutions, Inc. has agreed to place this in the public domain)

A central component of NABat is the use of a master sample of grid cells, a spatially balanced list of sampling areas within a continental grid framework. Conducting standardized monitoring within this framework allows statistical inference to unsurveyed locations. The master sample provides operational flexibility to partners while allowing for regional and rangewide analyses.

NABat gathers monitoring data to assess changes in bat populations using:

  • Mobile acoustic surveys along driving transects
  • Acoustic surveys at stationary points
  • Winter hibernaculum (location of hibernation) counts
  • Maternity colony counts
  • Emergence counts

Anticipated Products and Outcomes

  • The State of North America’s Bats: annual and multi-annual reports of status and trends in bat distributions and relative abundances (YEAR)
  • Spatially-explicit data on bat populations (e.g., improved range maps, density estimates) that will allow natural resource managers to identify areas and species of conservation concern
  • Long-term distribution data for addressing cross-boundary issues related to bat management and conservation
Image: Scientists Entering Mine

Scientists enter abandoned mine where bats hibernate in New York. (Credit: Kim Miller, USGS. Public domain.)

Accomplishments to Date

  • 252 registered projects in 42 states, 6 Canadian provinces, and Puerto Rico
  • 2,856 NABat GRTS cells claimed for survey
  • 1,496 GRTS cells with survey data uploaded
  • 8,633,339 acoustic files uploaded to NABat database
  • Release of, a website to support and disseminate information, user resources, and training materials
  • Publication of a spatially‐enabled database to house NABat data and metadata
  • Release of data visualization tools based on the NABat sample design, including mapping features to explore project data (private) and a public data map to identify current monitoring efforts and project details
  • Release of a new cell selection tool with numerous data layers, mapping features, and functionality to upload spatial objects and user-generated layers
  • Development of an automated project reporting feature for stationary acoustic and winter hibernacula data
  • Publication of the NABat Attributed Master Sample: a spatially balanced ordered list of sample units for each U.S. state and Canadian province
  • Interagency partnership with the U.S. Fish and Wildlife Service to utilize the NABat database as part of the Species Status Assessment for three North American bat species
  • Statewide volunteer mobile transect survey program implemented in North Carolina
  • Active engagement by U.S. and Canadian coordinators, state management agencies, and private conservation agencies
  • Four workshops and a technical report: A Plan for the North American Bat Monitoring Program (NABat). The report describes rationale, need, sampling design, sampling framework, guidelines for data collection, data management capabilities, and analytical approaches
  • Establishment of 4 NABat working groups to refine survey methods and collaboratively address research needs and emerging conservation issues
  • Partnership with the U.S. Forest Service to merge the BatAMP database with NABat
  • Partnership with the National Parks Service to merge bat acoustic data collected at National Parks across North America with the NABat database