Dataset: Lottia gigantea body temperatures from biomimetic loggers collected from the eight California intertidal sites from Jul 2023 to May 2024

We recorded body temperature at 8 sites across the geographic range: Bodega Marine Reserve, Dillon Beach, Fort Ross, Hopkins Marine Station, Kruse Ranch, Soberanes Point, Scripps Coastal Reserve, and Vandenberg. These sites included all sites from which we collected community data (except Seal Beach), plus Scripps Coastal Reserve. Note, we were unable to collect growth data from Scripps Coastal Reserve, because heavy barnacle recruitment obscured limpet tags and we did not deploy loggers at Seal Beach since friable rocky substrate made it difficult to secure loggers.

We estimated body temperature by deploying 6 biomimetic loggers at each site (ElectricBlue Robo Limpet). Loggers were set to record temperature every 30 minutes and were deployed in summer 2023 for 10-12 months. We attached the loggers to the substrate by filling a shallow depression in the rock with marine epoxy (Zspar Splash zone compound) and pressing the logger slightly into the epoxy. Loggers were deployed in gently sloping rocky shore habitats in the mid-intertidal zone, surrounded on 1-2 sides by mussel beds. Within 20-30 cm of each logger, we tagged 2-4 owl limpets (Shell length 30-45 mm) and recorded their growth rates to relate habitat temperature variation with performance.

From each logger, we calculated the upper 95^th percentile temperature in air, lower 5^th percentile temperature in air, mean immersion temperature, and the coefficient of variation for all recorded body temperature estimates. To determine aerial temperatures, we filtered logger readings for those recorded within 90 minutes of the largest daily low tide to ensure aerial exposure. To determine immersion temperatures, we filtered logger readings to include only those recorded within 90 mins of both daily high tides.