Where did this lot come from?

I could walk blindfold around Cwmbran Boating Lake and still come up with a reasonably accurate species list, but yesterdays chesse and pickle sandwich visit was an exception. Not one, two, three or four but no less than 46 pochard were counted with a couple of tufted duck thrown in good measure. So unusual was this occurrence that both species of diving duck represent new records of the site for me. The birds were very unsettled and flighty so much so that 19 of the birds left the lake during my brief visit.