Mountains support high levels of biodiversity due to their complex climatic gradients. Increases in elevation are accompanied by changes in atmospheric pressure, temperature, and solar radiation, which lead to differences in predation pressure, food availability, and energetic requirements for species. These environmental differences may prompt hormonal changes along elevation gradients, although few studies have investigated this relationship. Glucocorticoids are steroid hormones that influence metabolism, the immune system, and are used to maintain homeostasis. This study investigates avian glucocorticoid levels during the breeding season along an elevation gradient in west Texas, an area predicted to be a hotspot for climate change. We present preliminary results from two field seasons and discuss them within the context of the ongoing project. Understanding differences in the passerine bird stress response as elevation increases may indicate future probability of survival as climate change forces elevation range shifts in these species.