Wildfires and their Impact on Wildlife

Wildfire occurrence and severity are on the rise, as can be seen with the recent fires in LA. In addition to the worries about human life, there is also much to worry about regarding local wildlife and how the fires impact them. Climate change is a major cause behind the increase in wildfires around the world, due to warmer temperatures and drier conditions. These conditions also lead to the more intense wildfires seen in recent years. It becomes more and more difficult for wildlife to adapt to repeated catastrophic fires in their habitats, as quality habitat areas continue to decrease each year with little time for regrowth and recovery before the next fires come.

The long-term effects of these severe wildfires on wild animals are unknown, but recent research has been looking at the immediate and shorter-term impacts, mainly on hoofed animals and small mammals. When a wildfire is actively burning, most wildlife flees the area much like humans do. But after the fire is gone and the burned area is left, the impact on animals and their behaviors can vary by species. For deer, the fire often clears vegetation and leaves room for new growth, so they may continue to inhabit burned areas, whereas smaller mammals like mice have been shown to be more common in unburned areas rather than their previous, burned habitat.

A recent study found that wildfires and recently burned areas do impact mountain lion behavior and habitat selection. These animals choose to avoid burned areas, shifting their range to unburned areas with more vegetation. Because mountain lions hide and wait to ambush their prey, vegetation is important for their hunting strategies, which may be part of why they avoid burned areas after a wildfire. This shift in range and movement also causes behavioral changes and places the mountain lions at greater risk of encountering humans. This study observed mountain lions becoming more active during the day and they were found crossing roads more often than before the wildfires, putting them at risk of collisions with vehicles. As habitats continue to decrease in size due to not only human activities, but consistent fires every year, the animals are pushed closer to human-inhabited areas as they avoid the fires and subsequent burned areas. 

These fires also cause injury to wildlife and put them at risk of starvation. Mountain lions have been found with burned paws after a wildfire, which could prevents them from hunting and may result in starvation and ultimately death. So even animals that survive the initial fire may still die days or weeks later, succumbing to injuries or starvation. Beyond these shorter-term impacts, more research is needed to understand how these annual fires change the behaviors and lives of wildlife, especially in an increasingly urban world. Successful conservation of mountain lions and other local wildlife relies on our understanding of their habits and the risks they face.

References

Blakey, R. V., Sikich, J. A., Blumstein, D. T., & Riley, S. P. D. (2022). Mountain lions avoid burned areas and increase risky behavior after wildfire in a fragmented urban landscape. Current biology, 32(21), 4762-4768.e4765. 

Brookshire, B. (2022, October 28). Mountain Lions Pushed Out by Wildfires Take More Risks. ScienceNews. https://www.sciencenews.org/article/mountain-lions-wildfires-risks-road-crossing

Clark, H. (2024, March 6). Extreme Wildfires Take a Toll on California Wildlife. U.S. Forest Service. https://www.fs.usda.gov/about-agency/features/extreme-wildfires-take-toll-california-wildlife

Ganz, T. R., DeVivo, M. T., Kertson, B. N., Roussin, T., Satterfield, L., Wirsing, A. J., & Prugh, L. R. (2022). Interactive effects of wildfires, season and predator activity shape mule deer movements. Journal of Animal Ecology, 91(11), 2273-2288. 

Horncastle, V. J., Chambers, C. L., & Dickson, B. G. (2019). Grazing and wildfire effects on small mammals inhabiting montane meadows. The Journal of Wildlife Management, 83(3), 534-543.