I counted 11 Snipe sunning themselves then started to pack up. Whilst doing so, a familiar birder approached, though I think I've only seen him once before. I told him about the Oyc and he responded with, "I've just seen a Brent Goose". Some frantic questions revealed that he had seen a lone Brent Goose feeding in a newly sown crop field just to the north of the patch, but only by some hundreds of yards. He had seen it 45 minutes earlier, but had lost it after it had flown south and was checking to see if it had flown in here - it hadn't, but I was now on the hunt - surely I hadn't missed a flyover Brent! I first checked the fields immediately north of the pit to no avail, so I decided to revisit the site of the original sighting.
Parking by the farm shop and walking north about 100yds, I had a good view over several fields to the NE and almost immediately espied a lone Brent Goose feeding 2 fields over - it was very distant. After a few minutes, a Red Kite landing too close for comfort flushed the goose and it flew off south gaining height - to the pit I thought, but as it neared the road and the edge of the patch, it doubled back and finally landed slightly closer just 1 field away. It was still distant, but I was now struck by how pale the flanks looked and by the obvious demarcation between the dark neck and the paler breast - could this be a Pale-bellied? I was struggling to remember the possible variability in Dark-bellied, so didn't want to make a false call. I took some record shots, which are below, though heavily cropped, but before I was able to get home and look at them, a phone call and then a text book that Graham S fortunately had in his car, said that a key feature in Pale-bellied is the lack of a dark belly between its legs. Though distant, this bird seemed to show a white belly here - surely it was a Pale-bellied. I was never confident in ageing it either at the distance it was, but the cropped photos appear to show an adult.
I was soon due to pick the kids up from school, but first I stepped back into the northern edge of the patch and was pleased to be able to see the goose through a thinning hedge. Eventually, after picking the kids up and various ferrying trips, I was able to review the record shots, plus google images, Collins et al and feel fairly confident that this is indeed a Pale-bellied Brent Goose, only the second seen in Bucks - thanks to John H for the tip off! Apparently Mike C couldn't find the bird around 2:30pm after some local shooting had started up, but I hope it gets relocated and is a bit closer!