This year has produced two milestones in scientists’ understanding of the migrations of North America’s shorebirds.
Early this year, we reported on researchers who tracked Long-billed Curlews by satellite and discovered divergent migration habits of different breeding populations.
Now an article in the May issue of The Condor: Ornithological Applications describes, for the first time, the migration routes and timing of Marbled Godwit, a species of high conservation concern.
Bridget E. Olson, a wildlife biologist with the U.S. Fish and Wildlife Service, and two colleagues tracked 23 godwits from selected breeding populations from 2006 to 2010.
Birds from the largest population, which stretches across the grasslands of the northern Plains states and southern Canada, flew south in two directions. The majority migrated through Utah, stopped over at the Bear River Migratory Bird Refuge near Salt Lake City, and overwintered along California’s Salton Sea, wetlands in Baja California, or coastal areas in western Mexico. By contrast, birds nesting in North and South Dakota migrated southeast to the Atlantic coast of Georgia.
Even more surprising was the route flown by an isolated population of godwits, numbering no more than 2,000 birds, breeding on the shores of James Bay in eastern Canada.
Ornithologists had assumed the birds migrated along the eastern seaboard to wintering areas on the Atlantic coast. Instead, they flew southwest to the western coast of Mexico. Moreover, in Minnesota and South Dakota their route crossed the path of the Georgia-bound godwits. It’s the first proof of a continental crisscross migration pattern in a shorebird.
Read the abstract
Bridget E. Olson, Kimberly A. Sullivan, and Adrian H. Farmer, 2014, Marbled Godwit Migration Characterized with Satellite Telemetry, The Condor: Vol. 116, Issue 2 (May 2014), pp. 185-194. Abstract.
A version of this article appeared in “Birding Briefs” in the December 2014 issue of BirdWatching. Subscribe.