So they've gone now.  The last of the swallows, about fifty of them, left on 4 September.  They are probably over France somewhere by now.  
Our skies seem very empty without them, despite the daily gangs of starlings (not enough for a murmuration) and finches, the ever-present flock of seagulls, a few curlew and some oystercatchers.  
Roll on springtime.