Dosage Response of an Induced Defense: How Sensitive Are Tadpoles to Predation Risk?

Investment in defense and cost of predator-induced defense along a resource gradient

“…However, accurately estimating realized predation rates or quantifying chemical cues ( Not all studies exploring costs of defenses in tadpoles and other systems are consistent in their findings. Opposite patterns in growth rates, size at metamorphosis, and survival in response to (non-lethal) predators were found (Werner and Anholt 1996;DeWitt et al 1999;Van Buskirk 2002;Benard 2004;Hoverman et al 2005). Some of this variation might be due to different adaptation to various predator types and different defense strategies of prey species (Laurila et al 1998;Hoverman et al 2005).…”

“…I think that defense in tail depth and swimming activity was expressed at their maximum across the resource gradient, which explains why none of the models outlined in the introduction was supported by these traits. Some support for this explanation comes from studies that show that defense is limited and levels off when predation risk continues to increase above a certain threshold (Van Buskirk and Arioli 2002;Relyea 2004;Teplitsky et al 2005). Support for my findings and disagreement with the theoretical models comes from studies that manipulated resource availability.…”

Sedentary prey facing an acute predation risk: testing the hypothesis of inducible metabolite emission suppression in zebra mussels, Dreissena polymorpha

“…An effective induction of a defensive phenotype requires the prey to assess the predation risk (Gabriel et al, 2005), which can involve recognizing predator diets (Brown & Dreier, 2002); sensing the type (Lowen et al, 2013), size (Kobak et al, 2010) and abundance of predators (Van Buskirk & Arioli, 2002); or estimating the spatial position relative to a predator (Cooper, 2006). A time lag between detecting a predation cue and developing a defensive phenotype is critical to the effectiveness of the defence and thus plays a role in the evolution of inducible defences (Czarnoleski & Muller, 2014).…”

Multiple fish predators: effects of identity, density, and nutrients on lower trophic levels

“…This may indicate that fish density reduced the grazing activity of herbivores through non-lethal effects. Such traitmediated indirect interactions (TMIIs) are facilitated, for example, by predator cues or chemicals from crushed conspecifics (Behrens Yamada et al 1998, van Buskirk & Arioli 2002 and have the potential to induce cascading effects (Werner & Peacor 2003, Schmitz et al 2004. TMIIs are typically changes in prey behaviour, such as a reduced activity, and depend on prey density and the concentration of predator cues (van Buskirk et al 2011).…”