HOBOs, Tidbits and lizard models: the utility of electronic devices in field studies of ectotherm thermoregulation

1. A replicated experiment tested the null hypothesis that stand-alone elec tronic temperature recording devices produce sets of operative temperatures similar to those produced using lizard models. 2. Commercially available electronic temperature recording devices (HOBO XT (TM) with external probe and Tidbit(TM)) produced sets of operative tempera tures nearly identical to models designed to mimic the size, shape, scale a rchitecture and colour of two species of common North American lizards. 3. Tidbits(TM) performed better than external probes. 4. These results suggest that electronic devices (especially Tidbits(TM)) c an be substituted for models in many applications and that size, morphology , scale architecture and colour contribute very little to temperature chang e in small-sized life-like models widely used in field-based studies on the thermal ecology of vertebrates. 5. Small differences between temperatures recorded by electronic devices an d detailed Lizard-shaped models fitted with thermal probes suggest that the se models may nevertheless be necessary for certain kinds of studies.