Differential habitat use and antipredator response of juvenile roach (Rutilus rutilus) to olfactory and visual cues from multiple predators

Abstract

The indirect, behavioral effects of predation and predator-predator interactions can significantly alter the trophic ecology of many communities. In numerous instances, the strength of these effects may be determined by the ability of prey to identify predation risk through predator-specific cues and respond accordingly to avoid capture. We exposed juvenile roach (Rutilus rutilus), a common forage fish in many brackish and freshwater environments, to vision and/or olfactory cues from two predators with different hunting methods: northern pike (Esox lucius, an ambush predator) and European perch (Perca fluviatilis, a roving predator). Our results demonstrated that responses of roach to perceived risk (as evidenced by their selection of structured or open-water habitats) were highly dependent on cue type and predator identity. For instance, roach responded to olfactory cues of pike by entering open-water habitat, but entered structured habitat when presented with a vision cue of this predator. Opposite responses were elicited from roach for both olfactory and visual cues of perch. Interestingly, roach defaulted to selection of structured habitat when presented with vision + olfaction cues of either predator. Moreover, when presented individual cues of both predators together, roach responded by choosing open-water habitat. Upon being presented with vision + olfaction cues of both predators, however, roach strongly favored structured habitat. Differences in habitat selection of roach were likely in response to the alternative foraging strategies of the two predators, and suggest that prey species may not always use structured habitats as protection. This appears particularly true when a threat is perceived, but cannot immediately be located. These results provide insight to the complex and variable nature by which prey respond to various cues and predators, and offer a mechanistic guide for how behaviorally mediated and predator-predator interactions act as structuring processes in aquatic systems.

Threshold effects of habitat fragmentation on fish diversity at landscapes scales

“…Recent work has highlighted emergence from structurally complex habitat as a significant predation gauntlet, even more so than the separate effects of using matrix habitat, following from the concentration of predators along habitat boundaries (sensu Martin et al 2010). Therefore, the ability of fishes to connect/colonize patches within a fragmented landscape may be largely regulated by rates of emergence from seagrass, which is well-defined at our mesocosm scale.…”

Species diversity defends against the invasion of Nile tilapia (Oreochromis niloticus)

“…The experimental design was substitutive; thus, the number of Nile tilapia and the total numbers of each species were the same in each group. All treatments were replicated three times (Griffen, 2006;Martin et al, 2010b). There were 60 individuals in each mesocosm and 20 fishes in each ecological system.…”

Diel variation in use of cover and feeding activity of a benthic freshwater fish in response to olfactory cues of a diurnal predator

“…However, use of the PVC tubes by bullies would also limit their ability to use visual cues. Other studies have shown a preference for more open habitat with a larger visual field when there is a perceived predation threat (see Rilov et al 2007), and only moving to more structured habitat when presented with a direct visual cue (see Martin et al 2010). Another interesting finding was that the overall proportion of times bullies were observed using cover between the two treatments was only about 0.1% different, possibly reflecting a cumulative diel use of cover with significant changes in periodicity only.…”

“…To supplement vision, fish may utilize olfactory cues for predator detection and avoidance (e.g., Brown et al 2000;Hartman and Abrahams 2000). Recognition of predators through chemoreception and resulting behavioural responses are well documented (e.g., Kelley and Magurran 2003;Martin et al 2010). Other cues used by fish include social, electrical and mechanosensory (Montgomery et al 1995;Hanika and Kramer 2000;Brown and Laland 2003).…”

“…Many studies have suggested that patterns of diel habitat use are a means of predator avoidance (e.g., Anderson et al 2007;Kattel and Closs 2007), and numerous studies have also documented an increased use of structure, or cover, by freshwater fish when exposed to the risk of predation (e.g., Eklov and Persson 1995;Stuart-Smith et al 2008). Martin et al (2010) demonstrated the increased use of cover by fish following the detection of predators by olfactory cues, but there is little experimental evidence for diel habitat use changes in response to olfactory cues alone. The primary aim of this study was to test whether a fish that is capable of chemical recognition of predators will alter its pattern of diel feeding activity and microhabitat use in response to olfactory cues from a diurnal predator.…”