Fire and land cover drive predator abundances in a pyric landscape

Abstract

Understanding the link between environmental factors such as disturbance events, land cover, and soil productivity to spatial variation in animal abundance is fundamental to population ecology and wildlife management. The Longleaf pine (Pinus palustris) ecosystem is an archetypal fire-mediated ecosystem, which has seen drastic reductions in land area due to fire suppression. Current restoration utilizes prescribed fire and hardwood removal, but little is known regarding how these restoration efforts influence predator spatial distributions and predator-prey interactions. We conducted a study to investigate how fire, land cover, and soil productivity influence spatial distributions of predators in a fire-mediated ecosystem. We conducted a 34-camera survey across Camp Blanding Joint Training Center, a military installation in northern Florida, and utilized N-mixture models to estimate relative abundances of mammalian predators. To conceptualize our results relative to managed prey species, we categorized predators into white-tailed deer fawn predators [i.e. coyote (Canis latrans), bobcat (Felis rufus), and Florida black bear (Ursus americanus floridanus)] and nest predators [i.e. raccoon (Procyon lotor), Virginia opossum (Didelphis virginiana), and nine-banded armadillo (Dasypus novemcinctus)]. Coyote (P = <0.001) and bobcat (P = 0.01), increased relative abundance with decreasing pyrodiversity, the number of unique time since fire values. Raccoon relative abundance increased with distance from recent burns (P = 0.02). Coyote (P = <0.001) and bobcat (P = <0.001) relative abundance also increased with proximity to hardwoods, while raccoon relative abundance decreased with proximity to pine (P = 0.02). Interestingly, there was a lack of detections of mesopredators [i.e. red fox (Vulpes Vulpes), grey fox (Urocyon cinereoargenteus), spotted skunk (Mephitis mephitis) and striped skunk (Spilogale putorius)] that were historically considered common throughout the Southeastern United States and longleaf pine ecosystems. Our results indicate that predator space use was altered by fire conditions and distances to pine and hardwood stands, which supports a predator management strategy that utilizes management tools commonly used in restoration and conservation of the LLP ecosystem to indirectly alter predator distributions, which has the potential to positively affect the management of important species within this ecosystem.