The Invisible Impacts of Wildfires on Animals

This summer, the world felt the anguish of deadly wildfires like never before. In Maui, Hawaii, wildfires claimed more than one hundred human lives. Animal deaths were never formally reported. The Maui fire was only the most recent in a growing trend as the world heats up. Since 2000, there have been 72,400 wildfires in the United States alone. These fires have burned an average of seven million acres of land annually—twice as much as was annually burned during the 1990s. In the 2015 wildfire season alone, over ten million acres of land were destroyed in the U.S. California is the state most prone to wildfires, losing 2,569,386 acres of land to 7,396 different fires in 2021. But wildfires are not a uniquely Californian nor an American problem.

In July of 2023, wildfires in Canada burned so enormously and rapidly that clouds in New York City turned char brown. During that month, there were 374 active fires reported in British Columbia and 126 in Quebec alone, while New England had 106. The Interagency Fire Center of Canada has reported 4,241 wildfires since the start of 2023. Over 27.1 million acres of land have been already burned in Canada this year alone. The National Forestry Database of Canada revealed that as of June, the quantity of land burned this year has eclipsed the amount of land burned in 1989, which had previously held the country's yearly record. Even after the fires begin to die down, they create an enormous amount of smoke, which can be lethal when inhaled in high amounts.

The Impacts of Wildfires on Animals

A wildfire, from its spark to its demise, causes numerous harms to nonhuman animals. Animals with spatial mobility issues, such as those trapped in factory farms or roadside zoos, can be burned alive if the fire engulfs their region. Even after a fire is contained, or for animals outside the immediate burn radius, wildfire smoke can do tremendous damage to animals’ lungs. Birds, for example, have high-powered respiratory systems which aids them during long flights such as migrations. Birds also have thinner lung structures that help take in and release oxygen. This makes birds more susceptible to all forms of air pollution, including smoke, as chemicals in the air make their way into their bodies more efficiently. While no significant studies exist between factory farm animals breathing in wildfire smoke and developing health diseases and later these risk factors passing over to humans through their diets, the link cannot simply be ignored.

Aquatic animals are similarly impacted by wildfire smoke. Cetaceans like whales and dolphins generally exchange eighty to ninety percent of the air in their lungs per breath, compared to humans fifteen to breath, compared to humans fifteen to twenty percent exchange. This rapid gas exchange, along with the fact that cetaceans lack certain defense mechanisms like mucus and sinuses, which function as filters for foreign objects, makes them even more prone to inhaling smoke particles.

The short- and long-term behavioral pattern changes in animals due to wildfires remains relatively unknown. In one study, researchers fitted GPS devices onto birds and monitored their flying patterns during the massive 2020 U.S. wildfire season. They noticed that as birds detect wildfires, they changed their migration routes. For example, many birds stayed a few days longer in the Pacific region before taking flight again. One bird in the study took an abnormal route, transiting in areas where its population did not exist. Animals that detect fires may often forego foraging food, ideal habitats, and mating sites. For larger animals, this means expending more energy and resting more in smoke-prone areas. The impact of migrations and the prey-predator relationship amongst many animals can have a massive long-term impact on the survival of species.

A further scientific study demonstrated that smoke could cause cognitive impairment in animals. In the study, male rats were exposed to smoke that imitated wildfires. Those males had offspring that were more agitated and exhibited signs of cognitive impairment. Other studies involving rhesus monkeys and captive bottlenose dolphins that had inhaled smoke from wildfires both showed signs of compromised immune systems and a higher rate of pneumonia with signs of possible lung damage.

What a Warming World Means for Animals

The vast majority (approximately eighty-five percent) of wildfires are anthropocentric. Deforestation of grassy pastures to make way for industrial animal agriculture makes areas even more vulnerable to catching fire, and increases the risk that fires spread far and wide. Climate change also means the destruction of acres of habitat, pushing many species into extinction cycles. As there are no significant long-term studies on the impacts of wildfires on animals, we cannot accurately predict what this means for the future of animals, but what we can do is exercise the precautionary principle and pivot our policies toward eliminating anthropocentric causes of wildfires.