Wildlife nutrition is an essential element of fitness, and contextualizing resource use within the broader framework of local and regional food webs is paramount to species health, function, and management.
An understanding of a species' life history and habitat requirements is incomplete without insight into nutrition. Traditional diet studies have relied on observations, stomach lavage, and scat analysis, all of which impart bias due to logistics, temporal scales, and differential digestion.
In contrast, intrinsic tracers such as biomarkers and naturally occurring isotopes provide a powerful alternative that integrate broader timescales, target resources assimilated and related routing or allocation, and offer non-invasive sampling schemes. Moreover, these techniques also provide opportunities for expanding inference by assessing resource use within a food web context, assessing the role of habitat change, trophic dynamics, and ecosystem stressors.
In collaboration with other USGS scientists, Federal and State agencies, and university researchers, examples from this project include new insights into wildlife nutrition and food web interactions of logistically challenging to study species (for example, polar bears, Stellar sea lions, seabirds), non-native species introductions (for example, reptiles), and economically important fisheries (for example, Pacific salmon).
Geology, Geophysics, and Geochemistry Stable Isotope Laboratory (GSIL)