Numbers building up? Migrating (arriving) Brent observed over the weekend

The question mark above is intentional - I haven't seen a Brent Goose myself (in the flesh) since last winter but have heard reports of birds being seen ariving in streams - flocks of some dozens, and amounting to hundreds overall, moving low over the sea down the Antrim coast over the late mornings/early afternoons over this weekend. So numbers must be building up. Other threads of evidence include the feathers which appear along the fringes of the northern mudflats and the washed up Zostera there too. I should really get the telescope out....