Collaborative Research: Fat metabolism and oxidative stress in migratory birds

University Of Rhode Island, Kingston RI

Investigators

Abstract

A fundamental aspect of organism-environment interactions is understanding how different physiological and biochemical processes are integrated across different levels of biological organization (molecular, cellular and whole-organism) to support an organism's performance in its natural environment. Migratory birds are excellent model systems for investigating such integrative questions because migratory birds are impressive endurance athletes that use primarily fats to fuel their flights, and diet strongly influences fatty acid composition of stored fat that in turn affects whole-animal energetics during exercise. Reliance on fatty acid oxidation to fuel high-intensity endurance exercise in birds is remarkable in part because it increases oxidative stress which must be dealt with by the bird's antioxidant defense system. In fact, human health requires a ready supply of dietary antioxidants to combat the free radicals produced as part of normal metabolism, and much contemporary medical research is focused on understanding how dietary antioxidants promote human health. The primary goals of the two proposed research projects are to experimentally determine how certain essential fatty acids stimulate fat metabolism in exercising birds, how the antioxidant defense system of birds responds to the increased oxidative stress associated with exercise, and how this interaction between fat metabolism and antioxidant defenses depends on changes in seasonal demands during fall and spring migration. The proposed research builds on the successful collaborative research and teaching programs at a primarily undergraduate (Sacred Heart University) and R1 research (University of Rhode Island) institution. The proposed research will allow URI graduate students to learn fatty acid analysis at SHU, and SHU undergraduates will help URI researchers with field work, captive bird studies, and laboratory analyses for measuring plasma metabolites as indicators of health in wild birds. The two PIs will continue their tradition of training undergraduate and graduate students by utilizing URI's enhancing diversity initiatives and SHU's collaborative with the inner-city Bridgeport (CT) public school system. The proposed research will also strengthen established collaborations with biologists in southern New England working for NGOs such as The Nature Conservancy, Audubon, and local land trusts as well as international collaborations (jointly supported by NSF International Science and Engineering (ISE) Section) with colleagues at the Advance Facility for Avian Research, University of Western Ontario, and Max Plank Institute for Ornithology, Germany. Currently, there is much public interest in dietary antioxidants and how they promote human health. Migratory birds offer an interesting model system for studying the role of dietary antioxidants and fats on fat metabolism during exercise because birds have relatively low rates of free radical production in spite of higher metabolic rates and much higher maximum longevity than mammals of similar body size. In addition, patterns of bird migration have been implicated in the dispersal of disease (e.g. avian flu) and migratory bird populations are declining due to the loss of suitable habitat for stopover sites during their migration. The PIs longstanding collaborative field studies in southern New England guarantees the results will continue to be used for land conservation and management efforts.