Our current NSF grant centers on whether and how social challenges prepare females for future social instability. For this project, we are using experimental manipulations of nestbox (nesting cavity) availability to generate social instability in the wild, and quantify immediate and lasting effects of this instability on behavioral and physiological traits in female tree swallows. Results thus far show that females respond to social instability with increased aggression, and we are working on mountains (!) of data collected this spring, to quantify effects of social competition on gene regulation, immune traits, and testosterone levels in blood.