Theory successfully predicts hiding time: new data for the lizard Sceloporus virgatus and a review

Economic hypotheses predict that prey in refuges after short-term encounters with predators decide how long to hide before emerging (hiding time) based on cost of emerging (predation risk) and cost of not emerging. Here, I report tests of predictions of these hypotheses for several cost of emerging and cost of remaining in refuge factors in the lizard Sceloporus virgatus by approaching lizards to elicit refuge entry, review tests of the predictions to evaluate the success of current models in predicting hiding time, and note parallels between models predicting hiding time and flight initiation distance (distance separating predator from prey when escape begins). Hiding times were longer under greater risk implied by faster, more direct, and repeated approaches and by greater proximity of the predator to the refuge during hiding. Lizards responded to costs of refuge use by emerging sooner when food was visible outside and when the refuge was substantially cooler than the lizard. In addition, lizards were more likely to enter refuges when approached rapidly and when cloudiness precluded effective thermoregulation by basking. Review of findings for lizards and other taxa revealed strong support for the predictions of cost-benefit models that hiding time increases with cost of emerging and decreases with cost of staying in refuge. Examination of parallel predictions by escape theory and refuge use theory emphasizes their fundamental similarity and led to identification of an untested prediction of refuge use theory.