I once refused to take off (R/W 24) as I could see a flock of geese crossing the take off path from right to left. ATC became a bit crinkly: “You’ll miss your slot, etc, etc”. Well I didn’t miss my slot, but I did miss the geese.
I see that Notams refer to migrating geese. That’s not strictly true (I write as an albeit not-too-serious bird watcher). They are COMMUTING geese moving between overnight roosts and feeding grounds.
Jack