Birds of Indian Subcontinent

ON DETERMINING THE SIGNIFICANCE OF EPHEMERAL CONTINENTAL WETLANDS TO NORTH AMERICAN MIGRATORY SHOREBIRDS (Sobre la Determinación de la Importancia de Humedales Continentales Efímeros para las Aves Playeras Migratorias Norteamericanas)

Publication Type:Journal Article
Year of Publication:2008
Authors:SKAGEN, SUSANK, Granfors, DA, Melcher, CP
Journal:The Auk
Date Published:2008
ISBN Number:00048038
Keywords:bias, Calidris, Calidris fuscicollis, Calidris fusicollis, Calidris himantopus, Calidris pusilla, Calidris pusillus, Ereunetes, Ereunetes fuscicollis, Ereunetes himantopus, Ereunetes pusilla, Ereunetes pusillus, Erolia fuscicollis, Himantopus, Micropalama himantopus, Scolopacidae, Xenus, Xenus cinereus
Abstract:ABSTRACT Conservation challenges enhance the need for quantitative information on dispersed bird populations in extensive landscapes, for techniques to monitor populations and assess environmental effects, and for conservation strategies at appropriate temporal and spatial scales. By estimating population sizes of shorebirds in the U.S. portion of the prairie pothole landscape in central North America, where most migrating shorebirds exhibit a highly dispersed spatial pattern, we determined that the region may play a vital role in the conservation of shorebirds. During northward and southward migration, 7.3 million shorebirds (95% CI: 4.3–10.3 million) and 3.9 million shorebirds (95% CI: 1.7–6.0 million) stopped to rest and refuel in the study area; inclusion of locally breeding species increases the estimates by 0.1 million and 0.07 million shorebirds, respectively. Seven species of calidridine sandpipers, including Semipalmated Sandpipers (Calidris pusilla), White-rumped Sandpipers (C. fuscicollis), and Stilt Sandpipers (C. himantopus), constituted 50% of northbound migrants in our study area. We present an approach to population estimation and monitoring, based on stratified random selection of townships as sample units, that is well suited to 11 migratory shorebird species. For extensive and dynamic wetland systems, we strongly caution against a monitoring program based solely on repeated counts of known stopover sites with historically high numbers of shorebirds. We recommend refinements in methodology to address sample-size requirements and potential sources of bias so that our approach may form the basis of a rigorous migration monitoring program in this and other prairie wetland regions.
Short Title:The Auk
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith