Dr. Cornelia Twining

My research program focuses on addressing the ways in which animals cope with nutritional challenges from the scales of macromolecules to ecosystems. While earth’s primary producers are limited by inorganic compounds and energy, animals face the additional challenge of acquiring a multitude of organic compounds, from vitamins to proteins, that they cannot make themselves and which are often species-specific. When an animal’s diet does not fulfill its physiological requirements, nutritional mismatches can result in problems ranging from reduced condition and survival at the individual level to decreased secondary production and food chain inefficiency at the ecosystem level.
A central goal of my research program is to understand how environmental pressures such as habitat degradation and phenological shifts under global climate change alter the nutritional environment for and affect fitness in physiologically constrained species. While primary producers at the base of some ecosystems provide animals with all of their required nutrients, other primary producers are either deficient in necessary nutrients or contain only their biochemical precursors. Because both energy and nutrients are essential for growth and reproduction, there is strong selection pressure on animals to adapt to nutritionally incomplete resources. Some animals have adapted by becoming efficient at converting available precursors into the crucial organic compounds they require while others cope by consuming prey that have already done the work of conversion for them, using high quality subsidies from other ecosystems, or foraging for specific rare nutrients. Although foraging-based adaptations require less in the way of biochemical machinery, they impose energetic costs through foraging and may expose animals to challenging environmental conditions. Moreover, nutritional mismatches with local resources can arise when nutritionally complete prey, subsidies, or rare resources are not available.

I focus upon highly unsaturated omega-3 fatty acids (HUFAs), which are important compounds for all animals, but are unevenly distributed across ecosystems. While aquatic primary producers are often rich in HUFAs, these compounds are extremely scarce at the base of terrestrial ecosystems, creating the potential for aquatic resources to subsidize terrestrial animals with HUFAs. I study how birds and other animals cope with the nutritional dichotomy between terrestrial and aquatic resources through physiological and behavioral means.

Research Interests

Freshwater and riparian ecosystems, aquatic ecology, ornithology, food quantity and quality, resource subsidies, highly unsaturated fatty acids, stable isotopes