Herring gulls on the move after breeding

Modern GPS tracking techniques allowed us to follow our Herring Gulls in unprecedented detail. We could now see how they commute between the colony and their nest and their preferred breakwater in Noord-Holland. We could see how the centre of a groynes is used to preen, digest, and rest, while the edges were used to forage. After all… the best mussels are there were the water is covering them the longest!

From Texel to Schoorl

From two recent ringing projects we learned even better how Herring Gulls appreciate the groynes in Noord-Holland. The birds breeding in IJmuiden, just to the south of the area with groynes, do visit the breakwaters during breeding, but most consider the flights apparently too long for purpose. Herring gulls from Texel, however, happily cross the Marsdiep area in exploit the groynes all the way down to Schoorl aan Zee (left map). Straight after breeding, when self-maintenance and rest are more prominently on the agenda, the IJmuiden birds move up north, invade the groynes all the way up to Texel to join their conspecifics from Texel. In winter the majority of both populations has dispersed in a southerly direction and the groynes become populated predominantly by Herring Gulls originating from Scandinavia, the Baltic and Russia.

Tracking a single bird