Data files for manuscript titled "Temperature influences lipid content in the red harvester ant, Pogonomyrmex barbatus". Excel file with 3 tabs: Metadata, Monthly Lipid Content, and 10 Day Lipid Content. Metadata is contained within Excel file that describes all variables for each tab. Abstract from paper: Temperature is one of the most important environmental conditions affecting physiological processes in ectothermic organisms like ants. Yet we often lack information on how certain physiological traits co-vary with temperature across time. Here, we test predictions on how one trait—lipid content—co-varies with temperature using a conspicuous, ground-dwelling harvester ant. We focus on lipid content as fat bodies are metabolically active tissues that are important for storing and releasing energy in response to demand, which could be vital for survival under variable temperatures. From March to November, we extracted lipids from surface workers of 14 colonies while simultaneously recording ground temperature. We first assessed if lipid content was highest during cooler temperatures when ants were less active and less metabolically stressed. In doing so, we found that lipid content of ants declined almost 70% from cool months (November lipid content = 14.6%) to hot months (August lipid content = 4.6%). We next assessed if lipid levels from a group of ants collected at a single time point could change by placing individuals into environmental chambers set at 10, 20, and 30°C (i.e. the approximate span of average temperatures from March to November). Temperature again had a significant impact such that after 10 days, lipid content of ants in the hottest chamber (30°C) had decreased more than 75%. While intraspecific variation in physiological traits often follows seasonal patterns, our results suggest fluctuations in temperature may account for a portion of the variance observed in traits like lipid content.