Density-dependent predation and predator preference for native prey may facilitate an invasive crab’s escape from natural enemies

Abstract

Native predators can confer biotic resistance through consumption of invasive prey. However, early in the invasion process, native predators may initially ignore an invader when it is rare and only increase consumption once it becomes abundant. Furthermore, the willingness of native predators to consume novel invasive prey may be in uenced by the similarity of the invader to other native prey species that are favored or familiar. Here we examined whether a native predator (the common mudcrab, Panopeus herbstii) consumes the invasive lter-feeding crab, Petrolisthes armatus as a function of Pe. armatus abundance relative to native prey and the similarity of Pe. armatus to native prey. Using choice experiments, we quanti ed consumption of invasive Pe. armatus when its abundance was either rare, equal, or more abundant than native prey that were either taxonomically similar (crab, Eurypanoepus depressus) or dissimilar (mussel, Geukensia demissa) to the invader. We found that the absolute consumption of invasive Pe. armatus increased as its relative availability increased, but only in treatments where the alternative prey was a native crab. This suggests that prior experience of the native predator with a similar prey may prime the predator to consume more invasive Pe. armatus. A hierarchical Bayesian analysis determined that both native prey species were preferentially consumed by the native predator Pa. herbstii even when native prey were rare or equal in abundance to invasive Pe. armatus. These results suggest that density-dependent predation plus a persistent preference for native prey by native Pa. herbstii predators may help explain how Pe. armatus escapes its natural enemies.

Generalist Predators Shape Biotic Resistance along a Tropical Island Chain

“…Web-builders and spiders with ambush hunting strategies may also be less effective predators of sessile insects such as mealybugs. Lastly, resident generalists can exhibit preferences for native prey, which may be outspoken early in the invasion process [ 74 ] or when a new invader sequesters plant toxins, e.g., as may be the case for P. manihoti [ 75 ]. Hence, for generalist ladybirds, spiders or ants alike, the nature and relative importance of (native, invasive) pest–predator and predator–predator interactions carries major repercussions for ecosystem functioning [ 76 ].…”

Conservation Value of Gunungan Wayang Kulit Purwa for Science Learning Materials

“…Another group of animals in the Gunungan in Wayang Purwa ecologically acts as predators, such as tigers, snakes, and eagles. Javanese tigers and eagles are classified as predators occupying the peak position in a food chain (Kinney et al, 2023). Predators existing in a particular ecosystem can compete for prey.…”