Leukocyte coping capacity (LCC) is a method that can be used to quantify granulocyte’s ability to produce a respiratory burst by measuring reactive oxygen species (ROS) release in response to stimuli. Thus, LCC provides a measure of granulocyte function. This technique has been used to assess stressors on immune function in terrestrial mammals and avian species. LCC has been minimally explored in reptiles. The objective of this study was to assess the feasibility of using LCC to quantify ROS release from granulocytes in a field setting and determine if LCC can be used as a proxy for white blood cell function in the Radiated tortoise (Astrochelys radiata) to assess wellness. A total of 87 previously confiscated A. radiata undergoing health assessments were used to characterize LCC. A total of twenty microliters of heparinized blood from each animal was used to measure chemiluminescence using a portable 3M Clean Trace NGi luminometer (3M, St Paul MN). Chemiluminescence measured granulocyte ROS production in-vitro via stimulation with phorbol-myristate acetate (PMA). Lucigenin was used to produce a light reaction allowing quantification of oxidative free radical release in PMA-stimulated and unstimulated samples. For each animal, chemiluminescence was measured at 5-minute intervals for 40 minutes following blood collection. Data showed granulocytes in A. radiata blood responded to stimulation with PMA to quantify granulocyte ROS production. LCCmax occurred 10-15 minutes following stimulation in all A. radiata samples. Further testing in experimental models using known stressors is warranted to assess the value of LCC in predicting chelonian wellness.