This time is 7.35am Monday morning, and the sun has just risen above the Mendip Hills, on the north Somerset coast.

And the Woodpigeons have begun moving northwards again, along the south Wales coast, reversing the journey they made a week or so ago. Their flocks – at least, the ones I can see – are smaller, in the tens and hundreds, not the massive flocks of several thousand birds I saw moving south.

Did they get to Land’s End and think ‘You’ve gotta be kidding me?’ Do the young birds tag along for the British section of the flight as a learning exercise? Are Woodpigeons like sheep that just mindlessly follow a leader? Do they get caught up in the fun, the exhilaration, the sense of adventure but then realise their limitations when they meet the challenge of a sea crossing? Do they somehow realise the grass, and the berries, are not greener on the other side?

Just as with their migration south, so with the move of smaller numbers back north, no one knows why they do it; why some carry on with their migration while others return back the way they came, and whether they return to where their journey originated or whether they stop off to overwinter somewhere different along the way. Woodpigeons are much more mysterious than you might think!