Moult migration

Canada geese coming in to the older wetland on the east of the Relief Channel. 
They gather here regularly in early autumn. I used to think they gathered together in order to prepare for migration but I learnt that UK Canada geese rarely migrate from the UK. 
What they are doing, as I understand it, is returning to an area where they feel safe so that they can moult and replenish their feathers. As they lose their flight feathers they are vulnerable to predators at this moment. 
They aren't stupid. The wetland they are gathering in is surrounded by a predator fence. They just have to watch they don't get trodden on by the cattle that are grazed there once nesting season for wetland fowl is over!