Evolution acts to shape aging rates within the set of ecological and organismal constraints that individual species experience. Biodemography seeks to understand the shape of age-dependent reproductive and mortality patterns and how they are impacted by these constraints (Carey and Vaupel, 2006). Although model laboratory organisms have been crucial to understanding patterns and causes of aging, there is great value in also studying the underlying evolutionary and ecological forces that shape rates of aging in the environment in which they evolved. In this paper we examine the biodemography of wild populations of three species (a turtle, a frog, and a snake). All are ectotherms, an understudied subset of the vertebrate taxa for understanding aging. Low metabolic rates coupled with a tendency for indeterminate growth, and thus increasing fecundity with age, lead to the prediction that general patterns of aging should be slower in these taxa. We focus on age-dependent differences in mortality (i.e., the shape or trajectory of mortality), describing basic patterns and determining how early-life and late-life exposure to poor environmental conditions shape these patterns.