Biogeographic Patterns, Predator Identity, and Chemical Signals Influence the Occurrence and Magnitude of Non-lethal Predator Effects

• Main Author: Large, Scott Isaac
• Other Authors: Smee, Delbert L., Stunz, Gregory W., Overath, Regina D., Shirley, Thomas C.
• Format: Thesis
• Language: English
• Published: 2011
• Subjects: Carcinus maenas; Nucella lapillus; Chemical cue; Chemical ecology; Nonlethal predator effect; Predator–prey interaction; Predator diet; Prey behavior; Dogwhelk; Green crab; Hydrodynamics; Intermediate consumer; Non-consumptive predator effect; Predator avoidance behavior; Microsatellite; Biogeography; Cancer irroratus; Cancer borealis; Jonah crab; Rock crab; Crab Rock
• Online Access: https://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10231

Predators can have large effects on prey populations and on the structure and function of communities. In addition to direct consumption of prey, predators often cause prey to alter their foraging behavior, habitat selection, and morphology. These non-lethal effects of predators can propagate to multiple trophic levels and often exert equal or larger effects upon communities than those of direct consumption. For non-lethal predatory effects to occur, prey must detect and respond to predation risk. While the importance of information transfer in this process has been realized, few studies explore how prey responses are influenced by predator characteristics and environmental conditions that influence the transmission of cues indicative of predation risk. In this dissertation I investigate factors that influence how a single prey species evaluates and responds to predation risk. Here, I examined: 1) the type and nature of cues prey use to evaluate predator risk; 2) how predator identity, predator diet, and the relative risk of predators influence prey response to predation risk; 3) how hydrodynamic conditions influence the delivery of predator cues; 4) how biogeographic trends in predator distribution influence prey response to predation risk; and 5) how genetic structure might vary according to prey geographic location and habitat. To address these questions, I used a common intertidal model system consisting of the rocky intertidal whelk Nucella lapillus (Linnaeus, 1758) and a suite of its predators, the native rock crab Cancer irroratus (Say, 1817), Jonah crab Cancer borealis (Stimpson, 1859), and the invasive green crab Carcinus maenas (Linnaeus, 1758). Nucella use chemical cues emanating from their most common predator (Carcinus maenas) and crushed conspecifics to evaluate predation risk. Nucella from different habitats experience different levels of predation risk, and Nucella from habitats with high levels of predation had larger antipredatory responses to predator risk cues than Nucella that experienced ...