Ecological context shapes the response of consumers to predation risk

Permanent URL: http://hdl.handle.net/2047/d20004941
Title:
Ecological context shapes the response of consumers to predation risk
Creator:
Matassa, Catherine M. (Author)
Contributor:
Trussell, Geoffrey C. (Advisor)
Vollmer, Steven (Committee member)
Grabowski, Jonathan Henry (Committee member)
Gouhier, Tarik (Committee member)
Bertness, Mark D. (Committee member)
Publisher:
Boston, Massachusetts : Northeastern University, 2014
Date Accepted:
April 2014
Date Awarded:
May 2014
Type of resource:
Text
Genre:
Dissertations
Format:
electronic
Digital origin:
born digital
Abstract/Description:
The fear of predators can alter the foraging behavior of prey and drive trophic cascades. Such nonconsumptive predator effects emerge because prey foraging choices are shaped by growth/predation risk trade-offs: increased safety often comes at the cost of reduced feeding and growth. The risk of predation can thus influence the structure and dynamics of ecological communities by determining when, where, and how much prey choose to eat. Moreover, the physiological stress imposed by high predation risk can alter how prey use the energy and nutrients they consume, extending the ecology of fear to ecosystem functions such as nutrient cycling and trophic transfer efficiency. A growing body of theory demonstrates that ecological context shapes how consumers balance growth/predation risk trade-offs, but more empirical work has been necessary to identify the mechanisms that link prey foraging decisions to their community and ecosystem consequences.

The following research uses a rocky intertidal system to test theoretical predictions for how prey should behave under predation risk and the ecological consequences of these behaviors. On rocky shores in New England, green crabs (Carcinus maenas) have positive indirect effects on important foundation species such as barnacles (Semibalanus balanoides) and mussels (Mytilus edulis) by altering the foraging behavior of dogwhelks (Nucella lapillus), voracious intermediate consumers. When exposed to the scent of predatory green crabs, dogwhelks spend more time in refuges and reduce their foraging rates on mussels and barnacles. By manipulating the physiological and environmental conditions experienced by dogwhelks, the laboratory and field experiments presented here demonstrate that the effects of predation risk on communities and ecosystems depend strongly on a variety of biotic and abiotic factors, each of which acts to shift the costs and benefits of foraging. The cascading effects of predators depend on the environmental and physiological conditions of the organisms that connect the tops and bottoms of food chains. Understanding the behavior of intermediate consumers allows us to evaluate the roles that predators play in the structure and dynamics of ecological communities and should serve to inform us of the contexts in which predator introduction or removal may be effective management strategies.
Subjects and keywords:
anti-predator behavior
energy transfer
predation risk
rocky intertidal
trophic cascade
Biology
Marine Biology
Terrestrial and Aquatic Ecology
DOI:
https://doi.org/10.17760/d20004941
Permanent URL:
http://hdl.handle.net/2047/d20004941
Use and reproduction:
In Copyright: This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the right-holder(s). (http://rightsstatements.org/vocab/InC/1.0/)
Copyright restrictions may apply.

Downloads