Logistic regression models (two separate models) predicting presence of any putative clinical sign of upper respiratory tract disease among a frequency-matched cohort of Mojave Desert tortoises (Gopherus agassizii). Model 1: n=156, Model 2: n=130. Data were collected at initial health assessment (HA) between 2011–14 and at a subsequent HA in 2016 at two study sites: Large-Scale Translocation Site (LSTS; Nevada, USA) and Ivanpah Solar Electric Generating System (ISEGS; California, USA). Both models are adjusted for year of first sampling. Mycoplasma agassizii status based on parallel interpretation of species-specific quantitative PCR and enzyme-linked immunosorbent assay tests (see Materials and Methods for details). Mycoplasma agassizii conversion refers to change from Mycoplasma-negative status to Mycoplasma-positive status during the study period.a