Meeting Abstract

P3.9  Thursday, Jan. 6  A seasonal profile of adult condition in a long distance migrant, Franklin’s gull (Leucophaeus pipixcan) WEISSENFLUH, S.E.*; REED, W.L.; CLARK, M.E.; North Dakota State University; North Dakota State University; North Dakota State University shawn.weissenfluh@ndsu.edu

Environmental cues can influence the physiology of a variety of animals. Many of these cues are experienced seasonally and have significant effects on fitness, reproduction, and overall condition in animals. Considerable evidence indicates that reproducing later during a breeding season results in lower reproductive success (and therefore lower fitness). We have previously identified a maternal effect in eggs that varies seasonally and significantly affects fitness related phenotypes in offspring. In this study, we quantified the condition of Franklin’s gull (Leucophaeus pipixcan) adults nesting early and late in the breeding season, to evaluate whether the seasonal effect in eggs is associated with a seasonal change in physiological condition. We quantified adult condition in four ways: (1) with body condition indices, (2) with immune function using a bactericidal assay, (3) with chronic stress using heterophil to lymphocyte ratios, and (4) with plasma corticosterone response to a handling challenge. We hypothesize that birds nesting early in the season exhibit higher values of condition than birds nesting late in the season and these condition effects are translated to offspring through eggs. Understanding seasonal adult condition may lead to a better understanding of how changing climate may affect reproductive success in long distance migrants.