Meeting Abstract
Organisms are often challenged with balancing energy demand between competing physiological processes. For example, the demands of mounting immune responses can negatively impact reproductive success. Despite known costs of female reproduction, the mechanisms underlying parental behavior/physiology in immune-challenged female birds are unknown. Conceptually, reproductive life history trade-offs are not new, but no study has compared potential shifts in prioritization across stages of reproduction in female birds according to prior energetic investment. Breeding female zebra finches were injected with LPS or 0.9% saline on day 7 of incubation. Another cohort was injected similarly 7 days after hatching; a period of active provisioning. Nest attendance, flights, hops, and time at rest were recorded, and parental (and nestling) weights taken 0, 6, and 24 hrs post-injection. Blood was sampled at 0 and 6 hrs for CORT and PRL measurements. Our current data show that although LPS-treated incubating females significantly decreased activity (flights, hops), increased time spent at rest, and lost substantial mass this did not interfere with their parental behavior. Males increase time in the nest when their female mate is healthy. Analysis for nestling provisioning stage is underway. If trade-offs occur due to energy limitation, we predict females will maintain parental care during incubation but prioritize self-maintenance during increased energetic demands of nestling provisioning. Alternatively, predictions may be shaped by an investment perspective rather than purely energetic one, where individuals are likely to abandon a current reproduction when challenged in an earlier stage and likely to sacrifice self-maintenance at a later stage, given the amount of effort invested fitness.
