Most North American ospreys breed in northern latitudes and migrate long distances to and from tropical wintering grounds. Although the fall migration patterns of these ospreys have been well studied, very little has been published about spring migration. USGS and other researchers used satellite telemetry to determine the timing and duration of osprey spring migratory routes from 1997 to 2013. The researchers also compared spring and fall migrations among male and female ospreys from three breeding populations (east coast, midwestern, and western). Compared to fall migration patterns, all male and east coast ospreys spent fewer days on migration, traveled shorter distances overall, and traveled farther each day in spring. The mapped spring migration routes showed that ospreys minimize the time spent on migration to ensure a timely arrival on breeding grounds to establish or defend a nesting territory.
An osprey delivers a fish to a nest at William L. Finley National Wildlife Refuge. Photo credit: Edmund P. Schulz.
Author: George Gentry