| dc.description.abstract | Offspring performance and phenotype are affected by genotype and environment, which in birds includes yolk resources (part of the embryonic environment). Female colony nesting birds may influence offspring competitive ability in the post-hatching nest site environment by differentially allocating yolk resources to eggs based on nest site characteristics. Offspring performance may also be linked to prenatal allocation of resources, as well as post-natal parental care. Nest site characteristics, including nest size, density, and timing of breeding, influence the behavior (e.g., aggressive, social) and resource acquisition of the parents, as well as provide measureable variation in the postnatal environment. I used an experimental approach to quantify relationships among nest site characteristics, nest success, and offspring performance (growth and survival) in a nesting colony of Franklin's gull (Larus pipixcan). I also used a cross-foster experiment to examine tbe effects of parental care and provisioning on growth and survival of neonates. Timing of breeding, egg quality, chick quality, nest success and chick survival varied between the 2006 and 2007 cohorts. Nests in 2006 were initiated later than nests in 2007 and experienced lower nest survival rates but produced chicks in better condition. Chicks in 2006 also experienced higher survival than chicks in 2007; however, chicks in 2006 experienced slower growth. Timing of breeding may have influenced measures of nest and chick success examined in this study. In Franklin's gull, a trade-off between offspring quality and offspring quantity may be a consequence of migratory delays or unusual weather patterns in this long-distance migratory species. | en_US |
