Alterations and reductions of river flow have resulted in drastic changes to streamside areas of the Western US and throughout much of the world. Effects of these changes on plants have been documented, but effects on communities of land animals are less known. The degree to which animals rely on river water versus water from moist food may help predict how river alteration will affect streamside communities. Isotopes of water that are non-radioactive and occur naturally throughout the globe may be used to document the relative importance of these two possible water sources to animals. However, this technique is complicated by a change in water isotopes in the animal, over time, due to differences in evaporation between heavier and lighter isotopes. The proposed research will investigate a technique to avoid problems created by this phenomenon, using laboratory experiments on representative animal species.
The ability to use isotopes to document patterns of animal water use would be a great asset to biologists globally, especially those studying drylands, river and streamside areas, irrigated landscapes, and the effects of climate change. This project will incorporate undergraduate and K-12 students from diverse backgrounds, providing them with first-hand experience with scientific research.
