North American bats face a variety of threats that have caused precipitous declines in several species. Some of the most notable threats are described below, including diseases like white-nose syndrome, collisions with wind turbines, climate change, and habitat loss/degradation. In the face of these threats, it is necessary to understand whether individual bat populations can withstand these impacts or whether action is required to sustain viable populations into the future – and if so, how much is enough? These critical questions cannot be answered without knowledge of species' distributions and abundance and how these metrics change over time. Only then can we understand whether sources of impact truly threaten the viability of bat populations. This information also allows us to observe when species are rebounding and when species are stable and healthy.
The North American Bat Monitoring Program directly addresses the historic lack information on bat species status and trends through coordinated, standardized, long-term data collection. Data collected as part of NABat contribute to spatially-explicit estimates of bat distributions and abundance and how these metrics are changing over time. This information fills critical knowledge gaps that support the management of bat populations in the face of multiple threats.
White-nose syndrome (WNS) is a disease caused by an invasive, cold-growing fungus that affects hibernating bats. The fungus grows on bats’ skin, disturbing hibernation and resulting in dehydration, starvation, and often death. First documented in New York in 2006, WNS has since spread to numerous U.S. states and Canadian provinces, causing severe population declines in many bat species. Click on the button below to learn more or explore the WNS publications database.
Current estimates suggest that collisions with spinning wind turbine blades kill hundreds of thousands of bats each year in North America. Although it has been theorized that barotrauma, internal injuries caused by rapid changes in air pressure, may also contribute to bat fatalities at wind turbines, research shows this is exceedingly unlikely. Given that bats are long-lived and typically limited to 1 or 2 offspring per year, existing fatality rates may not be sustainable for some species. Recent studies indicate population-level declines are possible, particularly with the anticipated growth of wind energy development (see example wind energy future scenarios for the U.S. here). As a result, significant investments have been made in search of solutions that minimize impacts to bats without impeding the continued deployment of wind energy. Learn more from this webinar recording or click below to explore literature on this topic.
Climate change impacts bats in widespread and variable ways, altering multiple aspects of their ecology. Changing temperatures and extreme weather events, such as extreme heat/cold and increasingly arid environments, may produce unfavorable habitat conditions, change behavior, and influence the availability of insect prey or other food resources. As a result, bats may alter patterns of roosting, foraging, reproduction, and migration, and may even shift their ranges to find more favorable conditions.
Habitat Loss & Degradation
Forests and underground structures like caves and mines are critical bat habitat for roosting, foraging, and reproduction. The growing loss of these habitats, resulting from human activities such as deforestation, agricultural land conversion, mining, pest management, and urbanization, continues to cause substantial impacts on the abundance and diversity of bats at a global scale.