Project Summary:  Marine mammals that inhabit high latitude environments have evolved unique mechanisms to execute a suite of energetically-costly life history events (CLHEs) within a relatively short timeframe when conditions are most favorable. Understanding the intrinsic and extrinsic factors that regulate CLHEs is particularly important in species such as Weddell seals, as both reproduction and molt are associated with large reductions in foraging effort, and the timing and outcome of each appears linked with the other. The long-term mark recapture program on Erebus Bay's Weddell seals provides a unique opportunity to examine CLHEs in a known-history population. The proposed work will monitor physiological condition, pregnancy status, and behavior at various times throughout the year to determine if molt timing is influenced by prior reproductive outcome, and if it, in turn, influences future reproductive success. These data will then be used to address the demographic consequences of trade-offs between CLHEs in Weddell seals. The impact of environmental conditions and CLHE timing on population health will also be modeled so that results can be extended to other climates and species. 

An improved understanding of the interactions between CLHEs and the environment is important in predicting the response of organisms from higher trophic levels to climate change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. This project will support the research and training of graduate students and a post-doctoral researcher and will further foster an extensive public outreach collaboration.