Introducing a Stay, Shift, Go Framework for Behavioral Responses to Wildfire Smoke: American Robin ( Turdus migratorius ) Locomotory Behavior Changes as Particle Pollution Intensifies

Wildfire smoke is an increasing disturbance across much of the globe that has received little attention as a selective force in animal behavior. Animals may have evolved behavioral strategies to cope with smoke exposure, but what those strategies are and how they affect health outcomes are poorly described. Here we introduce a tiered "Stay, Shift, Go" framework to characterize animal responses to wildfire smoke disturbance. During periods of toxic smoke, animals may (1) stay, resisting changes in behavior (2) shift, altering their behavior to reduce negative impacts, or (3) go, relocating to places with cleaner air. Responses will be constrained by animal traits, such as locomotion, and may scale depending on the extent, duration, and intensity of smoke exposure. We hypothesized that American robins (Turdus migratorius), a highly mobile, partial migrant songbird living in a fire-prone habitat, would utilize a go strategy to avoid smoke from nearby wildfires during the postbreeding season. However, we found that they made shorter-distance movements as wildfire smoke intensified. Robins did not alter orientation behavior relative to the direction of the wind under light smoke, but they were more likely to orient into the wind when heavy smoke was present, which tended to reduce smoke exposure. Our results suggest that American robins shift their behavior during wildfire smoke events, potentially to reduce exposure to toxic air. While they do not immediately relocate, they may use different strategies as smoke becomes more intense-supporting our hypothesis that animal responses to wildfire smoke are complex and dose-dependent.