Since their arrival here in early May, swifts have not enjoyed the best of times.
The cool, wet, windy weather must have reduced the level of flying insects and spiderlings, the 'aerial plankton' they rely on.
In conditions of damp, muggy, low cloud, they fly just above open grassland or over trees where midges congregate. When the birds fly low it is possible to hear the snapping of their beaks as they zip past at speed all around me (see picture).
Alternatively, swifts may sometimes fly hundreds of miles to seek areas of high pressure in which to stock up with food for their nestlings but such long flights are nothing to them when they spend virtually all their lives on the wing.
However, nestlings might be left on their own for a few days before their parents return with swollen crops full of compacted food, known as a 'bolus'.
On a rare warm, still June evening, I'm sitting in the garden watching swifts. As they bank and turn, the low sun reflects off their under wings showing a golden sheen.
They fly with flickering wings seemingly quite slowly, then uttering their plaintive screaming cries suddenly accelerate and join up in pairs or small groups.
As dusk approaches, the last of the swifts filter into a whirling vortex of birds, like a twisting loose column, always in the same location as they rise to the heavens to roost, their cries becoming fainter and fainter.
Sadly, that column contains fewer swifts than I used to watch a decade ago.