Cooperative Fish and Wildlife Research Units Program: Nebraska
Education, Research and Technical Assistance for Managing Our Natural Resources

National Park Service (NPS) units in the Great Plains provide breeding habitat for many grassland birds. However, little is known about the quality of this habitat and more extensive study into the avian breeding ecology at these sites has been recognized as necessary. A short-term study on songbirds at three NPS properties complemented current NPS monitoring, providing an among park comparison of nest success—a prohibitively labor-intensive and expensive process when conducted on a regional scale. Park managers need lower-cost data for informed decision-making, and measuring site fidelity is a potentially less expensive means of monitoring breeding site quality. The project used unique methods—stable isotope analyses of avian tissues—to evaluate variability in site fidelity of grassland birds at three NPS units in the Great Plains: Homestead National Monument, Nebraska; Pipestone National Monument, Minnesota; and Tallgrass Prairie National Preserve, Kansas. Birds that breed successfully at a location will often return to that location again (site fidelity). Current extrinsic markers used in monitoring site fidelity were inadequate for small birds; stable isotope analyses provided an alternative. This project evaluated the extent to which stable isotope analyses could be utilized to measure site fidelity in breeding grassland birds, specifically four target species: dickcissel (Spiza americana), grasshopper sparrow (Ammodramus savannarum), eastern meadowlark (Sturnella magna), and western meadowlark (Sturnella neglecta).