Meeting Abstract
Animals live in complex environments where multiple environmental factors naturally co-vary. For instance, heat waves are often accompanied by droughts. Shifts in complex environments characterized by multiple, co-varying factors may lead animals to adjust life history (e.g., increased allocation of resources from somatic to reproductive tissues), behavior (e.g., increased dispersal or foraging) or physiology (e.g., reduced energy or water use). These biological adjustments may be cooperative. For example, combined conditions of heat wave and water limitation may result in reduced behavioral activity that, in turn, reduces energy use and water loss through respiration. Alternatively, adjustments may work antagonistically where, for example, stressful environments may result in a diversion of resources from immunity to somatic tissue. To investigate how water limitation and simulated heat waves alter life history, behavior, and physiology, we used a 2 x 2 factorial design to manipulate the thermal environment (field-parameterized heat wave or control conditions) and access to water (present or absent) in wing-dimorphic, variable field crickets Gryllus lineaticeps during early adulthood. After 4 days of treatment, we assayed behavioral exploration in a novel environment. We also measured rates of metabolism and evaporative water loss via flow-through respirometry, and assayed immune function (total phenoloxidase activity) in females. Last, we determined the key life history traits of survival and investment into tissue types (e.g., flight muscle status, and gonad and body mass). Our results will shed light on how complex environmental shifts influence several levels of biological organization in animals—from life history to behavior and physiology.
