A NEW OTM: A SPATIALLY AND TEMPORALLY EXPLICIT OPERATIVE TEMPERATURE MODEL

Ian J Axsom; Sequoia Riverlands Trust; Cal Poly, San Luis Obispo; iaxsom@calpoly.edu; William T. Bean

Environmental temperatures are a crucial aspect of ectotherm habitat quality. Operative temperature models (OTMs) have been an important tool for understanding the temperatures that organisms experience in their environments. While these physical models are inexpensive and easy to construct, they are limited to sampling a relatively small number of points in a landscape and thus fail to capture the full temperature variation that may be present. Recent research has demonstrated a way to create a spatially explicit OTM by combing traditional OTMs with drone data. Building on this work, we developed a spatially and temporally explicit model of operative temperature for our study species, the Blunt-nosed Leopard Lizard (Gambelia sila). We then used this model to test the idea that the spatial distribution of temperatures is important for ectotherms. Previous research had supported this idea but was limited to simplistic artificial environments. Our new spatially and temporally explicit OTM allowed us to test this in a complex natural system for the first time. Our work generally supported the idea that the spatial arrangement of temperatures on the landscape impacts ectotherm thermoregulation and movement. In addition to this, this new OTM may also serve as a useful tool for simulating changing environments and helping us better understand what impacts those changes will have on the temperatures that organisms experience.

Reptiles and Amphibians I   Student Paper InPerson Presentation