Kingfisher and Grey Wagtail

I went for a walk round the Reading University grounds by myself this afternoon.  Zoe stayed at home with Liz.  It had been a fairly cold grey day.  After half an hour in the campus bookshop, I walked back towards the Foxhill entrance.  The sun came out just as I was passing the weir at the north-western corner of the large lake, and I caught a glimpse of the red and irridescent blue of a kingfisher as it darted out from the north bank and flew off eastwards below the overhanging branches.  A few seconds later it was followed by a grey wagtail (Motacilla cinerea).  The person who named these birds chose to ignore their bright yellow fronts and instead concentrated on the upper part of their backs which is grey.