Meeting Abstract

10.4  Saturday, Jan. 4 08:45  Investment between reproductive and immune systems varies with latitude and time in Uta stansburiana SMITH, G.D.*; NEUMAN-LEE, L.; DURSO, A.M.; ZANI, P.A.; FRENCH, S.S.; Utah State University; Utah State University; Utah State University; University of Wisconsion–Stevens Point; Utah State University gdssmith57@yahoo.com

Environmental variation is known to elicit different physiological responses from animals living in those environments. In response to limited resources, animals must allocate energy reserves into competing systems. In some instances, increased reproductive output can maximize fitness in the short term, but increased immunological investment could increase lifetime fitness by allowing the animal to survive to subsequent breeding seasons. In our model, side-blotched lizards (Uta stansburiana), there is a wide gradient of lifespan across their large range. Northern individuals sometimes live seven or more years while southern individuals rarely live more than one or two breeding seasons. By using bacterial killing assays, in situ sonagraphy, radioimmunoassay, and oxidative-stress assays we are beginning to understand more clearly the relationships between the reproductive and immune systems, and how animals allocate resources among these systems. We have sampled populations from Oregon to Arizona for the last two years. When comparing populations at the same time of year we found that northern populations were allocating more energy into their immune systems than the southern populations, and less into reproduction, which corresponds logically with their longer potential lives and future reproductive opportunities. However, when comparing investment across emergence time and relative clutch number (i.e., first, second, third of the season) the relative investment pattern changes, suggesting that investment varies across years and the breeding season.