Repeated predatory attacks and multiple decisions to come out from a refuge in an alpine lizard

Prey often respond to predator presence by increasing theiruse of refuges. However, because the use of refuges may entailseveral costs, the decision of when to come out from a refugeshould be optimized. In some circumstances, if predators remainwaiting outside the refuge and try new attacks or if predator density increases, the prey may suffer successive repeated attacksin a short time. Successive attacks may represent an increasein the risk of predation, but the costs of refuge use alsomay increase with time spent in the refuge. Thus, prey shouldmake multiple related decisions on when to emerge from the refuge after each new attack. We simulated in the field repeatedpredatory attacks to the same individuals of the lizard Lacertamonticola and specifically examined the variation in successivetimes to emergence from a refuge under different thermal conditions(i.e., different costs of refuge use). The results showed thatrisk of predation but also thermal costs of refuge use affectedthe emergence decisions. Lizards increased progressively theduration of time spent in the refuge between successive emergencetimes when the costs of refuge use were lower, but tended tomaintain or to decrease the duration of time spent in the refugebetween successive emergence times when cost of refuge useincreased. Additionally, lizards that entered the refuge withhigher body temperatures had overall emergence times of longer duration. Optimization of refuge use and flexibility in theantipredator responses might help lizards to cope with increasedpredation risk without incurring excessive costs of refugeuse.