News Release

New Maps Allow Agencies to Better Protect At-Risk Bat Populations

Date: August 30, 2015
Contact: Kristy Burnett, 970-267-7205

FORT COLLINS: A new study of bats contains a breakthrough in understanding their ranges, demonstrating the importance of tree snags and cliffs for bats to raise pups and conserve energy during roosting. The results of the 8-year study also showed scientists which species were rare and which were more common, and the project established the foundation for coordinated monitoring of bats across North America.

Bats are not easily studied and are often misunderstood and perceived as scary and dangerous. But bats play a vital role in pollination, insect control, as well as seed dispersal, which translates to billions of dollars of ecosystem services. Bats face several threats, including fatalities from habitat loss, collisions with wind turbines, climate change, and the deadly fungal disease white-nose syndrome (WNS), which doesn't affect humans. WNS is rapidly spreading across the country and can wipe out 95 to 98 percent of a bat colony.

"This is an incredibly important project at a critical time for bats," said Tom Rodhouse, a National Park Service ecologist and the primary author of the study, which was recently published in the journal Diversity and Distributions. "The study was a leap forward for scientists because we created statistical models that can guide bat conservation efforts in a way that's not been possible before." 

The study, Establishing Conservation Baselines with Dynamic Distribution Models for Bat Populations Facing Imminent Decline, was completed by a team of federal agency and university research scientists that focused on bats and their habitats in the Pacific Northwest but opens the way for coordinated bat monitoring across North America. Rodhouse said the scope of the study is unprecedented for bats because they are difficult to track due to their nocturnal lifestyle. 

The study provides new range maps for 11 bat species across Oregon and Washington state. These maps graphically display information about population trends and the key habitat features that influence those trends. 

"The monitoring was how we discovered the regional pattern of bats using large dead trees called 'snags' to raise pups and that those snags are particularly important as nursery habitat," Rodhouse said. "Several species emerged as being rare and at particular risk of decline." 

The report established the foundation for monitoring bats across the entire continent of North America through an initiative called the North American Bat Monitoring Program (NABat) now underway. "The statistical models produce maps that live and breathe," Rodhouse said. "They tell the story of these bats over huge areas of the country and over time. Continued monitoring will let us update these maps and see how the story changes over time." 

Pat Ormsbee, a retired US Forest Service and Bureau of Land Management biologist and second author of the paper, emphasized the precarious endeavor of doing bat monitoring across such large areas. 

"To get the eight years of data used in the models took an enormous commitment from the involved agencies, and real blood, sweat, and tears from dozens of volunteer and professional biologists all across the region. To do this right takes focused investment that is desperately needed now more than ever with all the environmental changes going on," Ormsbee said. 

Ormsbee recognized this need early on and developed the interagency "Bat Grid" program to generate the monitoring data used in the study. This became the model followed by Rodhouse and others, including the study's third author, US Geological Survey statistician Kathi Irvine, to develop the NABat plan published earlier this year. NABat expands the Bat Grid's grid-based survey design across the continent. 

America's network of parks and protected areas, including those in the National Park system, supports populations of more than 50 bat species. Protecting bats and their habitats is a growing priority across these lands. Each year, millions of visitors explore parks, which makes them an ideal setting for engaging with the public about threats to bats, and consequently to the rest of the ecosystem. 

The full study is available here. For more information about this and other studies being conducted by the NPS Inventory and Monitoring Program, visit or contact Tom Rodhouse.

About Natural Resources Stewardship and Science. The Natural Resource Stewardship and Science Directorate (NRSS) provides scientific, technical, and administrative support to national parks for the management of natural resources. NRSS develops, utilizes, and distributes the tools of natural and social science to help the National Park Service (NPS) fulfill its core mission: the protection of park resources and values.

Last updated: December 2, 2015