- Yates, M, Boise State University, Raptor Research Center
- Fuller, M, US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, USA
- Schueck, L, Boise State University, Raptor Research Center, Boise, USA
- Seegar, W, US Dept. of Army, Edgewood, USA
- Young, G, Pennsylvania State University, Meteorology Department, State College, USA
- Thorup, K, University of Copenhagen, Zoological Museum, Copenhagen, Denmark
- Hedenstrom, A, Lund Universirty, Lund, Sweden
We radio marked adult female Arctic Peregrine Falcons (F. peregrinus tundrius) at nests in West Greenland, the northern Ungava Peninsula and Rankin Inlet, Canada, and on Assateague and Padre Islands, USA. During southward migration, falcons leaving Greenland often paused before crossing the Davis Strait. Some individuals stopped for 4 or more days during migration, but we found no consistent stopover strategy. Analyses of meteorological data from Canada and the USA during sample southward migrations suggest that peregrines are affected more by the winds on the morning of migration than by winds the morning after, and that tailwinds affect the likelihood of migration and the migration distance. Some falcons migrated near coastlines, but others made water crossings of more than 1,000km. However, detours from direct routes occurred commonly. Generally, the movement patterns are described best by geographical courses, and in no cases do the tracks indicate the use of constant geomagnetic courses. At least five Peregrine Falcons made a loop migration, southward along the eastern seaboard to Central and South America, then north into southern Canada via the central USA. Average migration rates varied from 142 to 282 km per day among bands of latitude. The average southward migration was 162 km/day and northward was 149 km/day.