HOW MIGRATION PATTERNS DIFFER
Most Dunlin that we see on British coastlines in winter breed in Arctic Eurasia, while our Knots are from the west, including Greenland and even Arctic Canada. In the spring, both Knot and Dunlin fly in bulk to the Waddenzee, off the Netherlands and Germany, to fatten up for their flights north. The Knot’s migration is remarkable, because they are thought then to fly to Iceland in one hop, and then on to their extreme northern breeding areas in another long flight. The Dunlin, smaller and less powerful, need not perform such a feat. They might take a short hop to FennoScandia, or as far east as the White Sea. They have no need for marathon flights. The point is, though, that as soon as the winter ends, these apparently similar birds begin to diverge in profound ways. They look suddenly very different, sound different and migrate in opposite directions. I would venture to suggest that it is then, and only then, that a Knot could be unmistakable from the Dunlin.