I could hear the Canadas as I parked at West Williamston - around 400, mostly in a field of cut hay on the N side of the Cresswell river 1 km away, the sound carried on the wind. Many concealed at first by the trees, you could only hear them. They were taking off in groups into the wind, then circling to fly upstream and land on the mudflats half way up the Cresswell river. Most were on the shore by the time I left. Around 40 greylags as well.
