Loss of body mass under predation risk: cost of antipredatory behaviour or adaptive fit-for-escape?

Fast growers sprint slower: effects of food deprivation and re-feeding on sprint swimming performance in individual juvenile European sea bass

“…Characteristics of individual animals, such as reproductive state, social status and life stage, also affect the willingness or ability to feed (Patton et al, 1970;Robin et al, 1988;Watts, 1990). High predator abundance can also reduce feeding opportunities, possibly leading to diminished growth or condition (Killen and Brown, 2006;Pérez-Tris et al, 2004). Many ectotherms can withstand weeks, months or even years of food deprivation without mortality (Biro et al, 2004;Hervant et al, 2001;Merkle and Hanke, 1988;van Ginneken and Maes, 2005), but food deprivation can have important sublethal effects on behaviour and physiology.…”

Increased predation risk modifies lizard scent‐mark chemicals

“…In contrast, chasings provoked loss of body mass in other lacertid species in natural (Martín and López,'99) and captive conditions (Pérez-Tris et al, 2004). Interestingly, previous studies with I. cyreni showed that the level of predation risk in natural conditions may be either associated (Amo et al, 2007b) or not (Amo et al, 2007a) with changes in body mass depending on season and environmental variables.…”

“…Lizards were individually housed at ''El Ventorrillo'' Field Station (Navacerrada, Madrid Province, Spain) 5 km from the capture site in outdoor opaque plastic cages (60 Â 40 cm) containing a shelter. To prevent interacting effects between predation risk treatment per se and feeding rate as a by-product when availability of food is variable (Pérez-Tris et al, 2004), feeding was limited to one Tenebrio molitor larvae of similar size every day. We ensured that all lizards ate the larvae each day.…”

“…Similar procedures have been recurrently used in other lizard studies to simulate increased predation risk in the environment (e.g. Pérez-Tris et al, 2004;Amo et al, 2007b). Control males were held under the same conditions but they were not disturbed.…”

Predicting population‐level risk effects of predation from the responses of individuals

“…In contrast, when starvation risk is high, energy stores (and body mass) will be increased to insure against starvation, but with the cost of a poorer escape performance (in terms of reduced speed, acceleration, and maneuverability) resulting in a reduced ability to escape from a predator (Krams 2002) and/or greater exposure to predation risk because of increased energy requirements linked to greater body maintenance costs (Brodin 2001(Brodin , 2007. MDPR theory was originally developed to explain energy reserve and body mass dynamics in small birds (Lima 1986, Bednekoff andHouston 1994), but evidence of widespread applicability now comes from a diverse range of vertebrate organisms in both terrestrial and aquatic ecosystems, including passerine birds (Gosler et al 1995, Gentle andGosler 2001), larger birds (Zimmer et al 2011), large aquatic mammals (MacLeod et al 2007c), rodents (Tidhar et al 2007), and reptiles (Perez-Tris et al 2004). The wide taxonomic applicability of MDPR theory makes this a useful test case for developing an understanding of predator risk effects.…”