Zwarte Zeeeenden Melanitta nigra snijden Nederlandse kust af

It has been shown that along the northern part of the Dutch coast spring migration of Common Scoters is much more pronounced than along the southern part, which does not seem logical in view of local winter distribution in recent years (Figure 1) nor with respect to considerable winter populations further south. Comparable regional differences have been observed in various coast-hugging species and among the suggested explanations the possibility of a short-cut of the curve in the Dutch mainland coast seems to be the most likely. The observation of a similar amount of migration in Noord-Holland as at Meetpost Noordwijk (9 km off Zuid-Holland) in spring 1978, with virtually no movements at all at the Zuid- Holland mainland coast (Figure 2) supports this idea. It is argued that the shortcut is more likely to be time-saving than an attempt to stay out of the polluted area around the Rhine mouth.