In On the Move, our regular column about migration, we present pairs of distribution maps from eBird that you can use to compare where interesting birds are at different times of year. We featured Greater Scaup, pictured above, in our December 2015 issue.
These maps compare distributions of Greater Scaup in June and December using eBird data from the last 10 years. The duck prefers bodies of still water — sheltered coastal bays and large inland lakes — where it dives to forage on bivalves, insect matter, and aquatic vegetation. It has nesting concentrations in the Aleutian Islands, western Alaska, the North Slope coastal plain, and along the western shore of Hudson Bay. Purple squares on the June map primarily fall in these areas, although oversummering birds (light purple squares), often subadults, show up along the Pacific and Atlantic coasts and in the Great Lakes. Most Greater Scaup winter along the Atlantic coast; the highest numbers are in Long Island Sound. Smaller numbers winter along the Pacific coast. San Francisco Bay is especially important.
Find Greater Scaup at these Hotspots Near You:
eBird is the real-time online checklist operated by the Cornell Lab of Ornithology and Audubon. “On the Move” is written by eBird’s Garrett MacDonald, Chris Wood, Marshall Iliff, and Brian Sullivan. Submit your bird sightings at ebird.org.
A version of this article appeared in “Birding Briefs” in the December 2015 issue of BirdWatching. Subscribe.
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