Sandpipers are already on their way south

Pulborough Brooks, West Sussex The sun is slowly dropping towards the horizon and the air is cooling. The sandpipers are still feeding, making the most of this important stopover site on their route

Ripples flow across the golden grass as the stems bend back and forth in the breeze. A pair of common blue butterflies - the male sky blue, the female rusty brown - dance over the field. It's quiet, apart from the tinkling of parties of goldfinches flying over, and the relentless buzz of crickets and grasshoppers rising up from the ground alongside the footpath.

I follow the track around the field and into the woods, and walk uphill to the Hanger, the viewpoint that looks out over the pools and channels of the brooks. Two young grey herons battle over the fishing rights to their small pool, raising the crests on their heads, holding their wings wide and barking sharp "frarnk" calls. Finally one gives way and heaves itself into the air, flapping slowly into the distance.