How does wildfire smoke affect wildlife? Here's what we know (2023)

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As climate change makes wildfires more frequent, scientists are racing to understand how animals suffer.

The smoke plume from the Dixie Fire—the largest single fire in California state history—got so huge it covered five states. It’s mostly contained now, but at its peak, people across some 2,500 square miles from California to Nebraska, were breathing in a variety of toxinsfrom the materials that fuel the fire, including ozone, carbon monoxide, and particulate matter. They were coughing, rubbing their stinging eyes, and having asthma attacks. For people who live in fire-prone areas, each new fire may be increasing their risk of stroke or heart attack.

People with HVAC systems and air filters usually can protect themselves by staying inside, but wild animals have no escape. As years of poor forest management and climate change cause fires to grow in size and intensity, it’s become increasingly important to understand how smoke affects animals, so that scientists can identify the most vulnerable species and determine whether they need management or conservation plans. Yet little is known about how wildfire smoke affects animals, and scientists are scrambling for answers.

“There are so many big question marks,” says Olivia Sanderfoot, a Ph.D. candidate at the University of Washington who published a study on October 19 in Environmental Research Lettersreviewing the existing research on how wildfire smoke affects animals. She found just 41 studies, most from the past 20 years. They included fewer than 50 species.

(Video) How wildfire smoke affects pets and livestock

“That’s not a lot of information on this topic, considering all the species potentially affected by wildfire smoke,” Sanderfoot says. “It leaves a lot of ground to cover.” For example, there are just a handful of mammals included in the research, and there are no published studies on how wildfire smoke affects amphibians, which breathe through their skin, or mollusks.

Why some animals are more vulnerable

“All animals that breathe air are vulnerable to inhalation exposure to wildfire smoke,” Sanderfoot says, adding that the threat depends on the physiology and metabolism of a species. Birds, for example, have highly efficient respiratory systems—they have thinner lung structures and can absorb oxygen both when they breathe in and breathe out. This means toxins in the air are transferred into their bodies more readily, making them more sensitive to all types of air pollution, including smoke.

Whales, dolphins, and other cetaceans also are especially vulnerable to smoke. They exchange as much as 80 percent of the air in their lungs with each breath, compared to humans at about 20 percent. They also lack protective structures such as sinuses and mucus to help filter out particles, Stephen Raverty, a veterinary pathologist at the Ministry of Agriculture in British Columbia told National Geographic last year. (Read more about how wildfire smoke affects dolphins and whales.)

Fishers, voles, ground birds, and other burrowing animals might be afforded some protection by their low-lying lifestyles, which can help reduce their exposure to smoke. Lower isn’t always safer, though, because smoke dispersion is affected by chemical composition, weather, and geography.

As in humans, symptoms of smoke-inhalation injuries in animals can include labored or rapid breathing, wheezing, panting, coughing, and foaming of the nostrils, Sanderfoot says. Carbon monoxide can lead to confusion, stupor, and death.

In addition, particulates can get deep into the lungs and trigger a long-lasting immune response and inflammation, harming respiratory and cardiovascular health, suppressing the immune system, and preventing cells from repairing themselves.

Male rats in a Russian lab that bred right after they were exposed to smoke that mimicked wildfires had offspring that were more anxious and showed evidence of impaired cognitive function.

(Video) Wildfire smoke and your health: what you should know | About That

Infant rhesus macaques living at the National Primate Center in California when it was inundated with smoke from regional wildfires in the summer of 2008 ended up with reduced lung capacity and weakened immune responses years later, in adolescence. Captive bottlenose dolphins in a U.S. Navy facility in San Diego showed higher rates of pneumonia, as well as evidence of probable lung injury following a major wildfire. Other marine mammals such as otters, seals, and orcas could have similar long-term effects.

Slowing down

Less obvious are the ways animal behavior changes in response to smoke. Like humans, most animals seem to find wildlife smoke unpleasant. Besides making it more difficult to breathe, for animals smoke makes it harder to see and smell food, whether that’s prey or flowers.

Many animals either flee or hide when they smell smoke, anticipating fire. The Algerian sand racer, a burrowing lizard in the Mediterranean region, doesn’t seem too bothered by wildfires that sweep the Iberian Peninsula. When it smells smoke, it hides, according to a 2021 study led by biologist Lola Alvarez-Ruiz, a researcher with the Desertification Research Center at the University of Valencia in Spain. She exposed two groups of the lizards—some from fire-prone areas and some not—to smoke and to a smoky, but odorless, control substance. “We saw that lizards that are living in places that historically burn a lot react more and detect the smoke better—and they hide. This capacity to recognize the smoke and respond is a way for the lizards to maximize survival,” Alvarez-Ruiz says.

What happens when smoke is everywhere, but there’s no fire nearby? “It’s very energetically taxing to enter fire avoidance strategies when there is no danger,” Sanderfoot says. Those that are able, like some birds and mammals, will use smoke as a cue to leave an area, but that means they forgo finding food and mating, expending energy to escape a fire that might never come near them.

Other animals respond to smoke not by fleeing, but by reducing their energy use. Researchers in Australia showed that small marsupials and some bats go into the low-metabolism rest state of torpor after fires to survive a lack of food. But researchers think that others, especially smaller burrowing animals that can’t outrun fires, might tuck themselves down deep into crevices, using smoke as a key to stay put as the fire rages overhead. But if there’s smoke and no fire, these animals’ torpor could mean that they are missing out on foraging for food and reproduction, says Clare Stawski, who studied how smoke affects the torpor of pygmy possums, dunnarts, and bats at the University of New England, in Australia.

“Smoke would probably also elevate their stress levels, which has its own bad consequences,” Stawski says. When an animal is stressed, it may redirect energy away from reproduction. Males stop producing sperm, and females skip estrus cycles. “They would also redirect resources from their immune system, which means that if they’re any underlying illnesses or if they're injured, for example, that they wouldn’t recover or heal properly,” Stawski says.

Larger animals slow down too. In Borneo, researchers began studying the effects that peat wildfire smoke in Borneo had on orangutans after noticing their voices sounded hoarse. The orangutans rested more and traveled less when inundated with smoke, even as urine samples showed the animals were still burning as much energy as usual, possibly to keep up their immune systems under stressful circumstances, says Wendy Erb, a postdoctoral researcher at the K. Lisa Yang Center for Conservation Bioacoustics at the Cornell Lab of Ornithology. “The orangutans are changing their energy budgets; they’re trying to compensate [by moving less], and yet they’re still going into this energy deficit state,” Erb says.

(Video) NYC on a normal day vs. NYC during the height of impact of smoke from Canada wildfires

Traveling less also means that Erb’s adult male orangutans had fewer opportunities to mate, and since orangutans have notoriously slow reproductive cycles, smoke could ultimately harm this already endangered animal’s population.

How to catch up—safely

So how are wildlife scientists going to catch up with the effects of wildfire smoke? Sanderfoot says the best way to study the effects of this smoke on animals quickly (and safely) is for ecologists and atmospheric scientists to pair existing data of animal behavior, like libraries of audio recordings and camera-trap images, with data from air-quality monitors

Community science can be helpful too. As long as it’s safe to do so, “collecting observations of wildlife during smoke events would definitely be useful,” Sanderfoot says. Platforms such as iNaturalist, eBird, and the Breeding Bird Survey allow anyone to upload photos and data of wildlife sightings, which scientists then use for various research projects.

In the meantime, gathering data from the field remains a challenge. Erb had to interrupt her orangutan study when the 2015 peat fire got so close that she and the rest of the research team had to turn to building makeshift hydrants in the peat and organizing firefighting teams instead of collecting data. “We actually don't have any data for the month when the air quality was the worst, because we were all putting out fires at that time. We put away our binoculars and took out our fire hoses for that month,” she says.

“And then it was like a miracle,” she says. “The sky [opened] up and it started pouring. And I don’t think that I’ve ever personally experienced that kind of elation....We’re just dancing in front of it. It was pretty amazing.”


How does wildfire smoke affect wildlife? Here's what we know? ›

These toxins can damage lung tissue, and lead to low blood oxygen levels or high blood carbon dioxide (CO2) levels. This can cause confusion and stupor, sometimes making animals more vulnerable to predation as they attempt to flee wildfires. Unfortunately, these lung injuries can last much longer than the fire itself.

How does smoking affect wildlife? ›

Deforestation: Another Way Smoking Impacts Wildlife

This not only contributes to climate change by releasing CO2 and removing carbon-absorbing trees, it also removes habitat for wild animals and increases the use of harmful pesticides.

How is wildfire smoke affecting birds? ›

But studies have shown that smoke can damage birds' lungs and make them more vulnerable to respiratory infections. And the fine particulate matter that is present in smoke — and causes well-documented health problems in humans — can also accumulate in birds' airways.

How does wildfire smoke affect us? ›

Inhaling smoke for a short time can cause immediate effects. Smoke irritates the eyes, nose, and throat, and its odor can be nauseating. Studies show that some people exposed to heavy smoke have temporary changes in lung function that makes breathing more difficult. People can also have changes in heart function.

What would happen to animals living in an area affected by a wildfire? ›

When wildfires erupt, animals do their best to move out of the direct path of the flames while staying close to home if they can find safe refuge. “Wildlife will move around their home area, avoiding the smoke and actively burning areas until it's safe to return,” explained Eyes.

Does wildfire smoke harm wildlife? ›

As irritating as smoke can be to people, it can cause health problems for animals as well. Smoke from wildfires and other large blazes affects pets, horses, livestock and wildlife.

How do wildfires affect wildlife? ›

Wildfire causes wildlife to move, avoiding flames and searching for new habitat. This migration can cause animals to wander into densely human populated areas and come into contact with humans they would normally avoid.

How does wildfire smoke affect bees? ›

When honeybees smell smoke, the effect is “like a fire drill on a submarine,” said Chris Conrad, owner of Bee Conscious Removal in Santa Rosa. Smoke disrupts the insects' alarm pheromones — that's why beekeepers often use small amounts of smoke when working on their hives.

Does wildfire smoke affect insects? ›

But not all insects fare well in the aftermath of wildfires. Huber says pollinators like bees and butterflies face challenges with respiration in the smoke-filled environment. "[Small particles] can affect the lifespan of some insects," he said. "[They] can get into those [insects'] airways and block them."

How does wildfires affect animals and plants? ›

Habitat Loss

Loss or contamination of shelter, water, and food are the immediate effects on wildlife following a fire. As such, animals are forced to move elsewhere in search of sustenance and new territory.

What are 3 effects of wildfires? ›

Increases in uncharacteristically large wildfires can exacerbate impacts on both ecosystems and human communities. Expanded areas of high-severity fire can impact tree regeneration, soil erosion, and water quality.

What are 4 effects of wildfires? ›

The effects of smoke from wildfires can range from eye and respiratory tract irritation to more serious disorders, including reduced lung function, bronchitis, exacerbation of asthma and heart failure, and premature death.

How does wildfire smoke affect plants? ›

Reduced photosynthesis translates to reduced energy, and weaker plants will display slow growth and diminished vigor. Additionally, with prolonged exposure, volatile organic compounds found in smoke can affect leaves and other plant parts and disrupt the ability of plants to take up nutrients.

What animals are most affected by wildfires? ›

Large animals like deer and elk will run away or seek refuge in rivers or lakes. Like any situation, sick, old and young wildlife are most at risk during a wildfire. Due to the fast-moving nature of some of these fires, it's likely that we also lose some otherwise healthy wildlife like deer and bear.

How are wildfires destroying animal habitats? ›

Invertebrate populations tend to decrease after a fire because eggs, food supplies, and/or shelter are destroyed. Flying insects are especially vulnerable because they are attracted to fire by heat or smoke and are incinerated in great numbers. Surface insect populations, such as grasshoppers, also tend to decrease.

Do trees grow back after a wildfire? ›

Many trees can recover after fire, depending on the intensity and duration of the burn and extent of dehydration. After a fire it is important to determine which trees might recuperate and which will need to be removed. Other less direct impacts include soil dessication or water-repellant (hydrophobic) soils.

What do animals do when they smell smoke? ›

Besides making it more difficult to breathe, for animals smoke makes it harder to see and smell food, whether that's prey or flowers. Many animals either flee or hide when they smell smoke, anticipating fire.

How does smoke affect deer? ›

Each individual's reaction to the scent of smoke could vary within the same context. An overcautious or timid whitetail will react in a very alert manner and be afraid of engaging the situation. Other bucks are so curious that they are far less likely to live long.

Is it bad to smoke near animals? ›

Increased respiratory disease: Just like people, pets who live with smokers are more likely to experience symptoms of respiratory disease, like asthma, bronchitis and lung cancer than pets that live in smoke-free homes. Cats are particularly susceptible to asthma flare-ups when exposed to secondhand smoke.

Is it bad to smoke in front of animals? ›

Smoking's not only harmful to people; it's harmful to pets, too. If 58 million non-smoking adults and children are exposed to tobacco smoke, imagine how many pets are exposed. Both secondhand smoke and thirdhand smoke hurt pets. Secondhand smoke is exhaled tobacco smoke and the smoke from the lit product itself.


1. How did wildfire smoke from Canada get to Europe? | About That
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2. Wildfire smoke from Canada making its way to Hampton Roads. Here's the latest.
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3. Canada wildfires: How will smoke affect health of Canadians?
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4. What we know about the wildfire burning in Northern Michigan that's 90% contained
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5. Canadian wildfire smoke creates air quality emergency
(ABC News)
6. Wild theories about what's fuelling Canada’s wildfires
(CBC News: The National)
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