Grant: Discovery Grants Program - Individual

Prey animals have at their disposal a variety of cognitive abilities, allowing them to respond to temporal and spatial variation in local predation risks. Key to this impressive degree of behavioural flexibility is the reliable acquisition of information regarding the presence, identity, and intensity of local threats. Within aquatic ecosystems, prey rely heavily on chemical and visual cues cues (public information) to continually update their assessment of risk and to optimize behavioural trade-offs. The availability of these cues, however, can be disrupted by a number of ecological parameters (i.e. pollution, turbidity, habitat degradation), resulting in impairments of cognitive processes such as learning and retention of predator recognition, and neophobia. However, studies examining the disruption of information typically manipulate the mean value of only a single parameter. In reality, prey are likely faced with multiple ecological parameters that may vary in space and/or time or parameters that may vary independently of one another. In light of the compounded (and often unpredictable) effects of climate change, habitat degradation, pollutants, and invasive species, the pressing question for ecologists is now how do prey respond to natural and anthropogenically induced heterogeneity of information across multiple ecological parameters? Here, using Trinidadian guppies as a model system, we propose a series of innovative laboratory and field experiments, addressing the question of how prey cope with variation of risk assessment information. Initially, habitat complexity is known to vary over fine spatial scales. The degree and variability of habitat complexity should influence the availability of visual and chemical risk assessment information. Our first objective will test the impact habitat complexity has on the spatial variability of information and resulting effects on cognitive abilities of prey. Secondly, due to episodic disturbances, risk assessment information may vary both in amplitude (`how much information is available') and frequency (`how often information is detected'). Our second objective will test the impact of `one large vs. many small' disruptions of information on the learning abilities of prey. Finally, prey are rarely, if ever, subject to variation in only a single ecological parameter. Rather, multiple parameters may either covary or vary independent of each other. Our third objective will employ controlled mesocosm studies, to systematically investigate the compounded effects of variation across multiple ecological parameters on the strength and retention of induced neophobia and learning in wild-caught guppies. Increasing our ability to predict the impact of variation across multiple forms of human disturbances on natural ecosystems will allow managers and conservation authorities to prioritize their efforts in an increasingly changing world. The current proposal was conceptualized to address this major knowledge gap.