Microhabitat and presence of top predators affect prey apprehension in a subtropical mountain forest

Citation metadata

From: Journal of Mammalogy(Vol. 99, Issue 3)
Publisher: Oxford University Press
Document Type: Author abstract; Report
Length: 611 words

Document controls

Main content

Abstract :

Most measures of predation risk have evaluated the baseline of risk according to habitat structure, when supplemental food availability was constant. Fewer studies have analyzed the effect of a predator's presence or abundance, and those studies have usually been conducted under controlled conditions or using scats, urines, or odors. We tested if apprehension in collared peccaries (Dicotyles angulatus) was affected not just by habitat structure but also by level of resource availability, and presence of top predators (puma [Puma concolor] and jaguar [Panthera onca]) in the immediate area. We classified microhabitats with different levels of risk based on vegetation structure, and compared apprehension of peccaries in shrubland, edge, and forest with sparse understory. To evaluate perceived predation risk, we used giving up densities (GUDs) in 3 trials with different food quantity. We related daily GUDs to predator presence, according to pictures recorded on trail cameras located around the experimental sites. The shrubland microhabitat was classified as the most dangerous, where peccaries were most fearful, while the edge and the forest interior were considered safer. Visibility was the habitat structure variable that most explained the levels of apprehension. Results from trials on days with the greatest numbers of predator photos were more similar among microhabitats, and peccaries left higher GUDs on the days when predators were photographed in the area. Food availability had a minor influence on GUDs. Sites and microhabitats that favor ambush cover are more risky for prey. Predator presence in the area modified temporally the perception of predation risk in prey, which expressed more apprehension and foraged less in the area at those times. La mayoria de los estudios de riesgo de depredacion evaluan el riesgo de depredacion base, de acuerdo a la estructura del habitat, cuando el alimento suplementado es constante. Pocos han estudiado el efecto de la presencia del depredador o su abundancia, generalmente bajo condiciones controladas o usando excretas, orina u olores. Nosotros evaluamos si el riesgo de depredacion en pecari de collar (Dicotyles angulatus) es determinado por la estructura del habitat, la disponibilidad de alimento y la presencia de depredadores en el area inmediata: puma (Puma concolor) y jaguar (Panthera onca). Basados en la estructura de la vegetacion clasificamos distintos microhabitats con diferentes niveles de riesgo, comparamos areas abiertas arbustivas, borde y bosque con escaso sotobosque. Para evaluar el riesgo de depredacion, utilizamos giving up densities (GUDs), en 3 experimentos con diferentes cantidades de comida. Probamos si la cantidad de GUDs se relacionaba con la presencia de depredadores registrados en camaras trampa, situadas en los alrededores de los sitios de estudio. Nuestros resultados soportan nuestras hipotesis, el microhabitat de areas abiertas arbustivas puede ser clasificado como el mas peligroso, donde los pecaries tuvieron mas miedo, mientras que el borde y el interior de bosque fueron mas seguros. La visibilidad fue la variable de habitat que mas explica los niveles de temor. Los experimentos con el mayor numero de fotoregistros de depredadores fueron los mas similares entre si, y los dias en que fueron fotografiados depredadores en el area, los pecaries dejaron mas GUDs. Mientras, la disponibilidad de alimento tiene una menor influencia sobre los GUDs. Sitios y microhabitats con cobertura que favorece una emboscada, son mas peligrosos para las presas. Aparentemente la clave es la visibilidad, y nos sugiere una banda umbral cercana a los 20 m para felidos grandes. La presencia de depredadores en el area modifica temporalmente la percepcion de riesgo de depredacion, las presas forrajean menos y tienen mas miedo en toda el area cuando estan los depredadores. Key words: apprehension, fear ecology, food availability, foraging behavior, giving up densities (GUDs), habitat use, predation risk, stalking cover, top predators, visibility DOI: 10.1093/jmammal/gyy046

Source Citation

Source Citation   

Gale Document Number: GALE|A545566938