first calendar year: November-December

By November, many LBBG have left the colonies and surrounding feeding grounds near the Maasvlakte (the Netherlands) and have migrated south towards France, Portugal, Morocco and Senegal. By mid-November, several 100's LBBG may still stay near the Maasvlakte, probably as long as it's not freezing. By December, a couple of hundreds remain on continental NW Europe, as north as southern Netherlands along the coast at Westkapelle, 65 km south of the Maasvlakte (see map). As it seems, every year a larger group of LBBG stay "at the most northern latitude as possible", i.e. migrate south only when winter conditions or food supply force them to. They feed out on the North Sea and follow coasters and fishing trawlers in mixed flocks of mainly Herring Gull (argentatus and argenteus) and (in winter only a few) Yellow-legged (michahellis) and Caspian Gulls (cachinnans). 

Year 2000 had a rather mild winter with temperatures below zero as late as mid-December. At Westkapelle, ringed individuals from Scandinavia, Denmark, the Netherlands, Belgium and Britain were present. When winter really started in December, this group moved south as well, to unknown wintering grounds, probably the Atlantic coast of Western and SW Europe. 

The first weeks of November 2001 proved to be mild again and several 100's of LBBG (many adults) could be found at southern locations in the Netherlands: the Maasvlakte and Westkapelle. As in the previous year, red colour-ringed juveniles from the Maasvlakte (the Netherlands), a green colour-ringed 2cy LBBG from Helgoland (Germany) and blue colour-ringed juveniles from Vest-Agder (southern tip of Norway) were present, together with several metal-ringed juveniles from Belgium, Britain, Norway, Denmark, Sweden and the Netherlands. Westkapelle seems to be one of the best places to watch graellsii and intermedius LBBG  together from a short distance.