Collaboration across organizations contributes to large-scale, long-term monitoring of North American bat populations.


By Kathy Gerst and Jessie Bunkley

Townsend’s big-eared bat, Jason Corbett

50 years ago, a bat species was observed foraging for insects in a field hundreds of miles from its known range today. 200 years ago, a cave was home to tens of thousands of bats and is now empty. And today, we see bats expanding their range to include habitats they never ventured into decades ago. We know many North American bat species are imperiled, but how do we know this? We need information about population sizes and ranges from before and after they encounter threats or experience change. This can be determined using long-term monitoring.   

What is ecological monitoring?  

Ecological monitoring is the regular observation of the presence and dynamics of populations. Some might think monitoring is the less thrilling sibling of scientific research, but they would be mistaken! Monitoring gives us a rich treasure trove of information about the past, present, and future of life on Earth. With historical monitoring data, we have a record of where species used to be found, when during the year they were there, and what they were doing. With current monitoring, we know what is going on in the present. By comparing current and past population dynamics and distributions, we can better understand the status of a species so we can help protect it. We can even investigate how changes we find in different populations relate to changes in the environment. And we can use this information to predict what may happen to species populations in the future.  

western small-footed myotis, Rachel Harper

So, how do we monitor bats?  

Bat Conservation International (BCI) collaborates with the North American Bat Monitoring Program (NABat) to standardize bat monitoring and understand the conservation status of bats across North America. To understand what is happening with our bat populations, NABat uses multiple types of data, including acoustics, colony surveys, and capture records.  If all biologists use the same methods for collecting this data to monitor bats at the same locations annually, we can compare data across time and space. This allows us to understand changes in species distribution across large scales as well as smaller, local levels. Armed with this knowledge, we can identify which bat species have populations that are declining and develop conservation strategies to protect them.  

One of the most specialized methods for monitoring bats is with acoustic monitoring. We use bat detectors, devices with specialized microphones for recording ultrasonic (pitches above human hearing) sounds that many bats make when they echolocate to hunt and navigate through the environment. Each species has a unique “shape” to their call, and we use both computer algorithms and human experts to determine which species made the recorded calls. 

Conservation means collaboration. 

Monitoring bat populations is important work that couldn’t happen without strong partnerships and collaborations. How else could we monitor sites all around North America at the same time? That is why Bat Conservation International is helping facilitate participation in the North American Bat Monitoring program through the PacWest and Southwest Bat Hubs. We have partnered with dozens of groups, including tribes, federal agencies, state agencies, and local conservation organizations, to make sure they have the resources they need to contribute to the NABat database and gain knowledge about the status and trends of bats on the land they manage so they can better protect local bat populations.  

Through NABat monitoring efforts, we have already learned that many North American bat species are in trouble from threats like white-nose syndrome. You can explore the status and trends of bats of North America on this site:   

Interested in contributing to ecological monitoring efforts? We encourage you to check out opportunities such as iNaturalist, Nature’s Notebook, and other community science efforts.  


Kathy Gerst is an ecologist who cultivates strong partnerships across science and management applications in the Southwest. She aims to bring together stakeholders, researchers, and agencies to ensure that science is collaborative and useful for the health and resiliency of ecological communities.  She enthusiastically promotes the use of standardized monitoring protocols and data accessibility. Over the past 20 years, Kathy’s work and interests have led her to carry out field research across mountains, deserts, and tropical rainforests. She speaks and publishes regularly on phenology and Sonoran Desert natural history. Kathy received a PhD in Ecology and Evolutionary Biology from the University of Arizona in 2011 where she studied plant reproductive ecology. Prior to joining BCI, Kathy worked for 9 years as a Research Scientist with the USA National Phenology Network. 

Jessie serves as the Conservation Research Coordinator for the PacWest region, facilitating and supporting bat-related research, management, and policy efforts in California and Nevada. Her research and conservation of a diversity of organisms, including bats, small mammals, shorebirds, seabirds, songbirds, reptiles, cetaceans, and numerous plant species, has inspired a wholistic, ecological approach to conservation and a commitment to public education and engagement. With a B.S. in Ecology and Evolutionary Biology from the University of California Santa Cruz, a M.S. in Biology from Boise State University, and professional experience with federal and state agencies, non-profits, and universities, Jessie contributes a deep and nuanced understanding of applied conservation to the talented team at Bat Conservation International.