Wildfires Play an Integral Role for Bat Populations: Study
Wed, April 14, 2021

Wildfires Play an Integral Role for Bat Populations: Study


Wildfires in recent years have become the deadliest and most destructive on record. Thousands of wildlife have been killed and thousands of homes have been destroyed. Fires in the Amazon sparked a global outcry last year. The National Institute for Space Research (INPE) revealed that more than 80,000 fires were detected across Brazil between January 1 and August 26, 2019 - a 78% increase in 2018 of more than 45,000 fires.

Statista, a German online portal for statistics, reported that last year’s recorded number of wildfires in Brazil was the highest since 2013. Unfortunately, fires are not only blazing in the Amazon but also in the Arctic, France, Greece, Indonesia, and many parts of the world. It’s important that scientists quantify and monitor these fires because they have a significant impact on global atmospheric emissions, with biomass burning contributing to the global budgets of greenhouse gases.

2019 data from the Sentinel-3 World Fire Atlas revealed that more than 79,000 fires were recorded in August last year. This was higher than 2018’s 16,000 recorded fires during the same month. According to Phys.org, an internet news portal that provides the latest news on science, of this figure, about 49% of fires were detected in Asia, 28% in South America, 16% in Africa, and the remaining were recorded in North America, Europe, and Oceania. "We have never seen an increase of wildfires of this kind since the ATSR World Fire Atlas was created in 1995,” Olivier Arino from the European Space Agency said. 

But, as wildfires continue to destroy the world’s wildlife and fauna, forests are learning to cope with the impacts. Recent reports show that forests in the western US are beginning to adopt prescribed burning. In the Sierra Nevada, only two wilderness areas allow for managed wildfires, where fires started by lightning can burn themselves out. This process not only benefits the forests but also wildlife, specifically bats. But, what exactly can prescribed burning do?



How Prescribed Burning Can Help

In stopping wildfires, countries should have enough tools and techniques, but not all nations have these. A scientific consensus has emerged to address this problem: prescribed burns. Prescribed burning, also called controlled burning, is all about setting planned fires to maintain the health of a forest. This involves having a clear plan to make sure the fire will not pose a threat to the public or to fire managers. This includes planning the details on how big the fire will be, what it will burn, and what managers hope to accomplish with the fire.

Also, plans map out how the fire will be set, how the smoke will be managed, how to inform the public, what protective equipment might be needed, and what firefighting resources should be standing by. The process can be done using dead grass, fallen tree branches, dead trees, and thick undergrowth. According to National Geographic, an American pay television network and flagship channel that is owned by National Geographic Partners, controlled burns can achieve several things: help prevent a destructive fire, reduce insect populations, and destroy invasive plants. 

“The crisis is not the number of fires, it’s that we have too many bad fires and too few good fires. It’s equally a problem that we’re not doing the good burning that would calm bad fires,” Stephen Pyne of Arizona State University, a leading scholar of forest fire history, emphasized. 



Bats May Benefit From Wildfires

For years, countries have made efforts to suppress the fires in the world’s forests as it only destroys habitats and kills animals. But, growing research shows that forest ecosystems have evolved to live with it and even rely on seasonal wildfire. Bat populations, particularly, are reaping the benefits of these wildfires.

Bats, which make up a large component of mammalian diversity in forest ecosystems, play an integral role as insect predators. Among the challenges that are threatening the bat populations such as habitat loss and climate change, wildfires are not one of them. A 2013 study published in the journal PLOS ONE suggests that bats are resilient to high-severity fire. Some species may even benefit from the impacts of fire on the landscape. 

"This is the first study to directly address species-level response by bats to stand-replacing fire, and our results show that moderate to high-severity fire has neutral or positive impacts on a suite of bat species," lead author Winifred Frick of the University of California, Santa Cruz, said.

According to UC Santa Cruz Newscenter, the study revealed that there’s no evidence of detrimental effects on bats in the southern Sierra Nevada mountains one year after the fire. The researchers used high-frequency microphones to record the ultrasonic echolocation pulses that bats use to hunt insects. Of the 16 bat species known to live in the area, the team identified six "phonic groups," including three individual species and three groups of species. Frick explained that these groups’ responses to the moderate and high-severity fire were either neutral or positive. This means that the landscape that the fires created resulted in a habitat structure that benefited the bat populations.

"Bats could be resilient to this kind of natural disturbance. We go out there and see a charred landscape and we think it's totally destroyed, but the bats may find it a productive habitat for their needs,” Frick added. 

These findings are supported by a recent study conducted by researchers from the University of California. The researchers found out that bats in the Sierra Nevada appear to be well-adapted to wildfire. Some species even preferred burned forests to unburned or minimally burned forests. The team used acoustic surveying technology with ultrasonic microphones to track echolocation patterns to learn how wildfire is affecting bat habitat. The recordings they gathered were converted into spectrograms, or visualizations of bat calls, allowing scientists to identify the species present.

According to Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, the researchers studied California forests in the Sierra Nevada Mountains affected by the 2013 Rim Fire, 2004 Power Fire, and 2012 Chips Fire. While individual bat species responded to wildfire differently, there’s an overall species richness increased from about eight species in unburned forests to 11 species in forests that experienced moderate- to high-severity burns.

"Bats rely on forests for a number of resources. The key is recognizing that natural fire is useful to them because it creates a variety of habitat conditions. They are adapted to it. Many species seem to actually benefit from fire,” lead author Zack Steel, a postdoctoral researcher, said.