Thermal benefitsofartificialsheltersinsnakes:Aradiotelemetricstudy of twosympatriccolubrids

1. Intemperateclimates,reptilesfaceconstrainingthermalconditions,andthustradeoffpredator avoidanceagainstthermoregulatoryrequirements. 2. Selectionofhighthermalqualityshelterscanentailsubstantialfitnessgainsbyenablingthe selectionofoptimalbodytemperaturesforphysiologicalperformance(e.g.,highbodytemperature for digestion),whilstminimizingpredationrisk. 3. Westudiedtwospeciesofsympatriccolubridsnakes(Hierophisviridiflavus and Zamenis longissimus) with contrastedthermalpreferencesinaforestedarea,offeringadiversityofnaturaland anthropogenicshelters.Individualsweremonitoredusingradiotelemetry.Physicalmodelswere used toassessoperativeenvironmentaltemperature. 4. Theexploitationofparticularartificialshelters,bothduringdiurnalandnocturnalphases,entailed importantthermalbenefitstothesnakes. 5. Aspredicted,themostthermophilicspecies, H. viridiflavus, usedhotsheltersmoreoftenthanthe less thermophilicspecies Z. longissimus