From August 13 to September 10, 2017, a juvenile Common Shelduck, Tadorna tadorna, was reported near Odiorne Point on the coast of New Hampshire.
Shelducks are Old World waterfowl that fill the gap between geese and ducks taxonomically as well as in their appearance and behavior. The Common Shelduck is a common bird across much of Eurasia and, in recent decades, has been expanding in Iceland. In 1990 breeding was first reported in Iceland, and a check of eBird map data today shows the birds being found all around the island in small numbers, but with some flocks as large as 550 birds!
With that booming population, it’s expected that a Common Shelduck will vagrate west into the ABA sooner or later. And so the deliberating has begun with some reasoning that this individual (and a couple others) might account for growing numbers of reports in New England, the Maritimes, and elsewhere in the East. The more conservative, meanwhile, demand evidence that these are not merely escaped domestic birds.
For the record, here are my documentary photos of the Odiorne Point bird showing wings, head, feet, etc: