Abstracts

Presented by Michael J. Anteau - Email: manteau@usgs.gov

With mounting concerns over wetland habitat loss and degradation is the need to understand those impacts on duck populations. However, concerns about habitat quality often manifest at small spatial scales and population dynamics are a lagging indicator of habitat conditions compounded through time and space. Moreover, great variation in habitat conditions at migratory stopover sites of species using large geographic ranges adds substantial uncertainty in using vital rates as an index of local or regional conditions. Nutrient and energy reserves of lethally collected ducks have often been used to inform suitability of habitat conditions, but reserves are also a lagging indicator and problematic for characterizing dynamic habitat conditions. Moreover, for portions of the ducks annual cycle when they are mobile nutrient and energy reserves represent habitat conditions at both unknown spatial and temporal scales. Over the past 20 years, avian researchers have been investigating lipid metabolite concentrations to index habitat conditions in real-time and at small scales. Lipid metabolites are isolated from blood plasma and can be assayed to determine levels of short-term lipid deposition or catabolism depending on concentrations. Here, we review published research along with our recently conducted research on several duck species during spring migration with the goal of communicating the role lipid metabolites may play in helping to evaluate habitat conditions. We will explore how metabolite concentrations vary in response to species, time, diet, and sex and discuss important assumptions of using this technique and common mistakes that can be avoided when collecting these types of data.