{"id":2209,"date":"2026-08-24T20:25:31","date_gmt":"2026-08-24T20:25:31","guid":{"rendered":"https:\/\/blogs.oregonstate.edu\/collegeofforestry\/?p=2209"},"modified":"2026-08-25T17:55:18","modified_gmt":"2026-08-25T17:55:18","slug":"wildfire-smoke-isnt-just-a-human-issue","status":"publish","type":"post","link":"https:\/\/blogs.oregonstate.edu\/collegeofforestry\/2026\/08\/24\/wildfire-smoke-isnt-just-a-human-issue\/","title":{"rendered":"Wildfire smoke isn\u2019t just a human issue\u2026 what about the wildlife?"},"content":{"rendered":"\n

By Lorelle Sherman, OSU Extension Forester<\/p>\n\n\n\n

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Smoke settles into the Umpqua River valley (photo credit Jon Cox)<\/em><\/figcaption><\/figure>\n\n\n\n

Every late summer, the air goes hazy, the sun turns an eerie orange, and I start checking the Air Quality Index (AQI) like it’s a weather app. Humans have gotten pretty good at talking about what smoke does to us \u2014 asthma flare-ups, N95 masks, canceled events. But what about the creatures who don’t have the luxury of running an air purifier? How does wildfire smoke effect wildlife in the Pacific Northwest?<\/p>\n\n\n\n

It turns out we’ve only recently started researching wildlife response to wildfire smoke. The strategies animals use to cope with smoke are still largely unknown. As wildfire smoke becomes an increasingly common disturbance in the PNW, the need to understand these strategies becomes increasingly important.<\/p>\n\n\n\n

What we do know\u2026 not all wildlife react the same way<\/strong><\/p>\n\n\n\n

It’s tempting to picture wildfire smoke as a blanket that shuts all wildlife activity down, or one that causes all wildlife to flee the area, but the data doesn’t support that. The reality is messier. A recent study led by OSU\u2019s Jamie Cornelius suggests framing wildlife response to smoke as \u201cstay, shift, go\u201d.<\/p>\n\n\n\n

Wildlife in very close proximity to wildfire will likely choose to flee the area, or go<\/strong>, to escape direct risk from the flames. However, species who are at no risk of being injured by flames don\u2019t always choose to flee. Some species choose to stay<\/strong>, reducing activity in place. Acorn woodpeckers were found to stay close to their home territory during smoke events, reducing social activity and the distance travelled while foraging. Other species shift <\/strong>their behavior without making long distance movements. Cornelius\u2019 team hypothesized that American Robins would flee from wildfire smoke events but found otherwise. Robins shifted their behavior by changing their orientation relative to wind direction in the presence of heavy smoke in an effort to reduce exposure to smoke.<\/p>\n\n\n\n

Some species appear to stay <\/strong>and carry on business as usual. A camera-trap study across eastern Washington landscape tracked eight species \u2014 black bear, bobcat, cougar, coyote, elk, moose, mule deer, and white-tailed deer \u2014 through smoke events. Black bear, cougar, coyote, elk, and white-tailed deer did not appear to change their behavior in a meaningful way during smoke events. Behavior and physiology don’t always move in the same direction, though, and an animal that looks like it’s carrying on as usual may be dealing with something much more costly under the surface (see orangutan example below).<\/p>\n\n\n\n

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A heard of elk feeding in smoky conditions (photo credit Leo Visions)<\/em><\/figcaption><\/figure>\n\n\n\n

In the Washington study, three species did respond to smoke events. Bobcats and moose were less active, while mule deer showed a small increase in detections during smoky periods. Moose are sensitive to environmental extremes, especially heat stress, so their reduced activity in this case may be due to compounding stressors. The authors suggest that mule deer moved towards smoke to avoid predation.<\/p>\n\n\n\n

It’s certainly not a PNW species, but Bornean orangutans monitored during a severe regional smoke event rested more and moved less. Outwardly, this appears to be an animal conserving energy. But when researchers checked their urine for markers of fat metabolism, the orangutans were actually burning more <\/em>calories than usual, likely fueling an immune response to the smoke itself. They looked calm. Internally, their bodies were working overtime.<\/p>\n\n\n\n

While much of our research is done on larger, more charismatic taxa like birds and mammals, there are some measured effects on our insect friends. Paper wasps have been observed pre-warming their flight muscles the moment they detect smoke, essentially idling the engine in case a fast escape is needed. Smoke exposure makes European honeybees less responsive to floral scents and alarm pheromones, which is part of why beekeepers have used smokers for centuries to calm a hive.<\/p>\n\n\n\n

The cost of staying<\/strong><\/p>\n\n\n\n

If you’ve ever walked through the forest on a smoky morning and noticed how still everything feels, you’re not imagining it. Researchers at 92 monitoring sites across central and eastern Washington recorded the dawn chorus (the burst of bird activity right around sunrise) through the smoke-heavy summers of 2019 and 2020. When a particularly hazardous smoke event blanketed the region in September 2020, the soundscape didn’t just dip for a day and bounce back. Bird song dropped noticeably during the smoke and stayed suppressed for two weeks afterward, even once the air had cleared.<\/p>\n\n\n

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An osprey sits on its nest enveloped in smoke (photo credit Marneejill)<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n

The two week lag suggests birds aren’t just waiting out a bad air day but something about the exposure has a lingering effect on their behavior. It could be altered foraging routines, temporarily vacated territories, or something more physiological we can’t determine from an audio recorder.<\/p>\n\n\n\n

A long-term bird-banding study in California looked at two decades of bird capture data on species that also nest here in the PNW, like sparrows, wrens, and warblers. In this study, researchers set up mist nets, large nets that are nearly invisible in the landscape, to passively capture birds. They found that birds get caught less often in mist nets right after a smoke event, but more often after repeated or prolonged smoke exposure. What may be happening here is when the wildfire smoke hits, birds go quiet and hunker down. Once the air clears, birds likely ramp up activity to make up for lost foraging time.<\/p>\n\n\n\n

Despite the secondary burst of activity, foraging time lost to smoke comes at a cost. Birds with more cumulative smoky days between two mist net captures had measurably lower body mass. Birds that endured ten or more high-smoke days had up to a 1.7% loss in weight. So, that means a bird that looks okay to us, flitting around a week after the haze lifts, may be running on emptier reserves than it looks.<\/p>\n\n\n\n

Loss of reserves is especially concerning when thinking about migratory birds. The energetic demands of migrating are usually fulfilled by an increase in foraging before and during migration. However, fall migration often coincides with wildfire events. If foraging is interrupted by wildfire smoke, the outcome of migration may not be favorable. Wildfire smoke can also directly affect migratory routes and navigation at ground-level and at migration altitudes. Bird species that are flexible in their flight altitude, path, and stopover sites will likely respond better to smoke than species that rely on traditional \u201cset\u201d pathways.<\/p>\n\n\n\n

Wildlife that move towards smoke<\/strong><\/p>\n\n\n\n

Wildfire smoke is a mixture of gases and particulate matter that has the potential to expose wildlife even hundreds of miles away to airborne toxins. We\u2019ve focused on terrestrial wildlife thus far, but wildfire smoke can influence aquatic ecosystems, too. Surprisingly, it\u2019s not all doom and gloom. Some insects are considered fire-loving, or pyrophilous, meaning they are attracted to wildfire and smoke. Beetles, like Melanophila acuminata<\/em>, depend on wildfire for reproduction because they lay their eggs in freshly burned wood. The beetles are unable to overcome a living tree\u2019s defense reactions, so they\u2019ve adapted to mate while fires are actively burning. Females lay eggs under the bark of freshly burnt trees. They are able to find forest fires from extraordinary distances (up to 50 miles) by detecting heat using specialized organs. Melanophila consputa<\/em>, the charcoal beetle, is commonly observed swarming on prescribed burns in the fall on the west coast. It sometimes mistakes people for trees and can give a little bite. For this reason, these beetles are well known to fire practitioners.<\/p>\n\n\n\n

Smoke flies in the genera Microsania<\/em> and Hormopeza<\/em> are known to swarm directly in active smoke plumes. While the reason for this attraction is unknown, they may be using the smoke as a meeting ground to find mates, like a fly nightclub.<\/p>\n\n\n\n

Predatory raptors and insect-eating birds have been observed using actively burning areas for hunting (pyric-carnivory). Grassland fires can create clouds of fleeing insects and expose small mammals. In a Great Plains study, the abundance of Swainson\u2019s hawks and several other raptor species increased seven times during prescribed fires compared with pre-ignition. While we aren\u2019t sure how hawks detect fires far from them, it can be inferred that they come for an easy meal.<\/p>\n\n\n\n

How smoke may benefit salmon<\/strong><\/p>\n\n\n\n

We\u2019ve focused on terrestrial wildlife thus far, but wildfire smoke can influence aquatic ecosystems, too. And in a favorable way! Pacific salmon and trout are cold-water adapted species, meaning they depend on cool river temperatures for survival and reproduction. Even though salmon are skilled at locating cold water in aquatic landscape, their distribution is constrained in the summer by high water temperatures.<\/p>\n\n\n\n

Researchers have long suspected that wildfire smoke reduced river water temperatures because smoke particles scatter and absorb solar radiation. This should reduce the amount of solar radiation reaching the Earth\u2019s surface, reducing air temperatures, and river temperatures\u2026 right? A 2018 study of Northern California watersheds validated these hypotheses when they found that wildfire smoke cooled water temperatures enough to be ecologically meaningful for salmon and trout. The caveat here is that wildfire frequently occurs under natural conditions in this ecosystem. The results may not be the same in locations where wildfire is human-caused and\/or more novel to the ecosystem.<\/p>\n\n\n\n

Final Thought<\/strong><\/p>\n\n\n\n

There’s still a lot we don’t know about how wildlife respond to wildfire smoke. However, what we do know suggests that mobile wildlife are resourceful. Somewhere out there, a charcoal beetle is mistaking a firefighter for a tree, a smoke fly is working a smoke plume, and a salmon may be enjoying a slightly cooler river. Wildlife in the PNW have been adapting to fire for millennia; the least we can do is start paying closer attention, and pushing for a future where the adaptations they\u2019ve already formed are enough to survive.<\/p>\n\n\n\n

Studies referred to:<\/strong><\/p>\n\n\n\n