When do you know it's really summer? Are you one of those people who think summer begins with the summer solstice? Or when the schools break up for the six-week holiday? Is it when test cricket starts, or the football season ends? For me it's when I see Red Bartsia in flower. There is always a mixture of pleasure at seeing it again and sadness that the year is yet again careering onwards. I then start to think of summer as becoming long in the tooth when I see the first Harebell - as much as I like what the autumn brings, an air of melancholia briefly visits me when the first pastel blue bell nods my way. From a moth perspective, a Copper Underwing in the MV leaves me in no doubt as to it being summer. Birds are trickier. My problem with 'summer' birds is that I reckon that the first signs of autumn passage appears as early as June, when waders such as Lapwings and Green Sandpipers start to bother the notebook. Therefore I'd plump for the flocking of young Starlings as the undeniable sign of avian summer. The messy, whirring flocks of squabbling birds, a patchwork of pale buff and early adult gloss plumage is as much a summer scene as ice cream vans, lobster pink shoulders and the smell of barbeques. As for autumn... I'll save that for later.