This is how wildfires in the American West are changing animal behavior

Wildfires have become a persuasive part of living in the Western United States, but did you these unplanned events are just as life-changing for the animals that live in America's forests as they are for the humans who experience them?

In the arid climate of the Western United States, summers are now defined by the intensity of their forest fires rather than the beauty of their nature. Burning homes, trapped wildlife, and resources stretched to their limits are now the hallmarks of life for those living in the American West. 

One of the worst years for forest fires ever recorded happened in 2020. Higher-than-average temperatures shattered a record that held strong for 2000 years and devastated the high-elevation forests. 

Climate change, the loss of pre-industrial controlled burning practices, and a century of suppressing every fire that popped up have created a doomsday scenario where fires are burning hotter, burning longer, and threatening more and more wildlife. 

But a 2022 study published in the American Ecological Journal revealed that wildfires aren’t just threatening wildlife populations, they’re changing their day-to-day behaviors. 

“As fire activity increases with climate change,” the study’s authors wrote in their abstract, “our findings indicate the impact on ungulates will depend on trade-offs between enhanced summer forage and functionally reduced winter range, mediated by characteristics of the predator community.”

All this means is that the increasing size and severity of forest fires have changed the way certain animal populations, like those of the western mule deer, look for food.

The study noted that the increased amount of burned forest canopy led to a number of knock-on effects that were completely unexpected. 

In much of the American West, forest fires have served a historically important purpose. Fires cleaned and cleared forest undergrowth and allowed eatable vegetation to flourish. 

More powerful and longer-lasting fires have burned away greater amounts of forest canopy and created highly productive regrowth zones that mule deer populations favor. Researchers found that in the summer months, deer populations would migrate toward these regrowth zones.

But during the winter months, mule deer populations avoided the areas of forest that had experienced more devastating and destructive fires, which begged the question: why? 

The researchers discovered that the increased level of the burned forest canopy, which made certain forest areas desirable in the summer, also led to increased levels of snowfall on those forest floors in the winter, a problem normally regulated by the branches of older and larger trees. 

Increased snowfall resulted in less eatable vegetation for mule deer and made it more difficult for the animals to traverse recently burned sections of forests. Plus it made the deer easier targets for prey. 

“Mule deer more vulnerable to carnivores since their hooves [sunk] into the snow,” the study’s researchers noted, “while predators like wolves and cougars have wide paws that [helped] them walk over the snow.”

The authors of the paper also pointed out that after a fire, regrowth and fallen trees provided the perfect cover for predators stalking their prey.

All of this influenced the behavior of where deer would travel to eat and where they would avoid to protect themselves from the wolves and cougars that preyed on them. In Washington state, the researchers found that deer were less likely to migrate through burned forests where the threat of cougar activity was high.

But the deer population's behaviors also seemed to be influenced by the severity of a fire or the amount of time since it had burned, an amazing conclusion that has helped researchers better understand how the changing climate will affect future generations of animals in the American west.