An update on my Yellow Wagtail counts at Garthorpe of a month ago. I never managed a count of more than 135 but 75-100 were still present for a week or so after 2nd August. Once crops along the road were cut, though, there were fewer there but we retained about 50 feeding behind our cattle until the end of August, when numbers abruptly declined (I didn't note it but I think it was 50 on 31/8 and 5 on 1/9. There were still 80+ roosting at Blacktoft Sands just over the border in Yorks on the 2nd though). Quite a number (30 or so) were feeding on the ground in nearby field beans - goodness knows what on - but so far as I could make out none roosted here. Since the start of September a few have remained, with seven today, the 11th.
Lincolnshire is becoming increasingly important for Yellow Wagtails. In the BBS in 2012, an amazing 25% of birds counted in the UK were in this county; this is not the same as saying 25% of the population is here (though that is not impossible) because it doesn't take differing levels of coverage into account - but it's still impressive. Equivalent figures for other farmland birds include 6% for Skylark and Linnet and 8% for Tree Sparrow. A look at the 2007-11 Atlas maps (see
http://blx1.bto.org/mapstore/StoreServlet?id=334) show how areas of high relative abundance are concentrated between east Yorkshire and the Fens. The most recent figure for the rate of their decline is 43% during 1995-2012. Now, bear in mind that apart from a small population along the coastal strip opposite Dover, Yellow Wagtail M f flavissima is restricted to Britain as a breeding bird. Hmm.