Impacts of predator‐induced behavioural plasticity on the temperature dependence of predator–prey activity and population dynamics

Abstract

Predation is a key ecological interaction affecting populations and communities. Climate warming can modify this interaction both directly by the kinetic effects of temperature on biological rates and indirectly through integrated behavioural and physiological responses of the predators and prey. Temperature dependence of predation rates can further be altered by predator‐induced plasticity of prey locomotor activity, but empirical data about this effect are lacking. We propose a general framework to understand the influence of predator‐induced developmental plasticity on behavioural thermal reaction norms in prey and their consequences for predator–prey dynamics. Using a mesocosm experiment with dragonfly larvae (predator) and newt larvae (prey), we tested if the predator‐induced plasticity alters the elevation or the slope of the thermal reaction norms for locomotor activity metrics in prey. We also estimated the joint predator–prey thermal response in mean locomotor speed, which determines prey encounter rate, and modelled the effect of both phenomena on predator–prey population dynamics. Thermal reaction norms for locomotor activity in prey were affected by predation risk cues but with minor influence on the joint predator–prey behavioural response. We found that predation risk cues significantly decreased the intercept of thermal reaction norm for total activity rate (i.e. all body movements) but not the other locomotor activity metrics in the prey, and that prey locomotor activity rate and locomotor speed increased with prey density. Temperature had opposite effects on the mean relative speed of predator and prey as individual speed increased with temperature in predators but decreased in prey. This led to a negligible effect of body temperature on predicted prey encounter rates and predator–prey dynamics. The behavioural component of predator–prey interaction varied much more between individuals than with temperature and the presence of predation risk cues in our system. We conclude that within‐population variation in locomotor activity can buffer the influence of body temperature and predation risk cues on predator–prey interactions, and further research should focus on the magnitude and sources of behavioural variation in interacting species to predict the impact of climate change on predator–prey interactions and food web dynamics.

The influence of predator community composition on photoprotective traits of copepods

“…Intrapopulation variation in astaxanthin expression is likely affected by factors such as heterogeneities in the light and resource environment (Cieri & Stearns, 1999 ), as well as predation risk by planktivorous fish. Our results are consistent with stickleback, and the predation risk they present, acting as agents of plasticity (Gvoždík & Boukal, 2021 ), and substantially lowering individual astaxanthin expression. It is unclear why stickleback might cause bigger differences among individuals at low content of astaxanthin expression (i.e., when predation risk is presumably the highest).…”

Functional response of larval and adult Coccinella septempunctata to eggs and larvae of Plutella xylostella on canola

“…Predator–prey interactions are a central theme to the practice of biological control of insect pests (Laws, 2017) and determine the effectiveness of biological control programs as well as the stability of ecosystem dynamics (Gvoždík & Boukal, 2021). Several attributes determine the success of a predator as a biological control agent, including the predator's feeding response to changes in prey density (Fernández‐Arhex & Corley, 2003).…”

A changing world: the role of phenotypic plasticity in host-parasitoid interactions facing extreme temperatures

“…translating to faster walking speed, shorter host handling time) and behavior (e.g., activity versus quiescence) (Abram et al, 2015;Augustin et al, 2020;Boukal et al, 2019;Moiroux et al, 2016). Species-specific differences in thermal tolerance will yield more complex outcomes at community than at individual level (Boukal et al, 2019;Gilman et al, 2010;Gvoždík & Boukal, 2021;Outreman et al, 2018). In an exemplary experiment, Davis et al (1998b) showed that the competitive outcome between three Drosophila species was driven by temperature, but that the addition of a competing species altered the focal species' thermal optima.…”

“…Behaviour is a highly plastic trait and can continuously adapt to match environmental conditions. Temperature affects many components of parasitic or predatory behaviour such as defensive behaviour, host or prey-encounter, attack rates and feeding rates (Gvoždík and Boukal, 2021;Lemoine et al, 2014;Moiroux et al, 2016). Changes in thermal conditions were also found to alter host-selection behaviour, and sex ratio of eggs laid by parasitoids (Moiroux et al, 2015(Moiroux et al, , 2014.…”

“…Although the effect of thermal fluctuations on the immune responses of hosts against their parasitoid has not been studied yet, an increase in rearing temperature led to an increased egg encapsulation of the parasitoid Tranosema rostrale Brishke (Hymenoptera: Ichneumonidae) by its larval host Choristoneura fumiferana Clemens (Lepidoptera: Tortricidae) (Seehausen et al, 2017). Yet, events of high extreme temperature may not always destabilise consumer-resource interactions due to opposite thermal effects on each species, such as prey encounter rates or walking speed (Bannerman et al, 2011;Boukal et al, 2019;Gvoždík & Boukal, 2021). Additionally, thermal stress can alter parasitoid attack rates and the defensive behavioural responses of hosts (Bannerman et al, 2011;le Lann, Lodi, et al, 2014).…”