Fig 1. Interaction between a mesopredator and its prey (*), which can be influenced indirectly by a top-predator (a) or another mesopredator (b).

Controlling Mesopredators: importance of intraguild behavioural interactions in trophic cascades

Populations of large predators have been overfished and decimated from oceans worldwide. Loss of predation force (top down control) has triggered trophic cascades and phase shifts due to the explosion of small consumers (mesopredators) that deplete resource prey species. Using a reef fish food web I experimentally study how the effect of small predators on their resource prey can be modified by: 

  • Predation risk from top predators  (Fig 1a)
  • Intra/ interspecific guild interactions (Fig 1b). 

Understanding the behavioural interactions among predators and its impact on trophic cascades is indispensable to predict consequences of predator loss and design appropriate management policies on coral reefs. 

Project details 

Objective: Study how top-predators (coral trout) indirectly influence the behaviour and physiology of resource prey (baby damselfish).

Location: Lizard Iisland. Great Barrier Reef

Time frame: Oct 2013 - March 2016          

Publications so far:

Palacios MM, Warren D & McCormick MI. 2016a. Sensory cues of a top-predator indirectly control a reef-fish mesopredator. Oikos 125: 201-209.

Palacios MM, Killen SS, Nadler LE, White JR & McCormick MI. 2016b. Top-predators negate the effect of mesopredators on prey physiology. Journal of Animal Ecology.