1st August

August got underway just as July had ended, with precious little reason for departing migrants to drop out of a night sky so lit by the full moon that it seemed like darkness never really fell. Willow Warblers again scraped into double figures at the Bill and made up the bulk of the numbers on the ground; visible passage there was more conspicuous, with SwiftsSand Martins and Swallows trickling through for a good part of the day. A Little Ringed Plover was new at Ferrybridge and seawatching at the Bill came up with 54 Manx Shearwaters and singles of Balearic Shearwater, Great Skua and Yellow-legged Gull.
Migrant lepidoptera included what looked to be a small arrival of new Painted Ladys at the Bill and singles of Small Mottled Willow and Bordered Straw amongst small numbers of regular immigrants in the Obs moth-traps.

presumed adult and juvenile Swifts - Portland Bill, 1st August 2015 © Martin Cade

...for no good reason other than they were swooping about rather enticingly over the Obs garden we spent a while attempting to photograph Swifts during the afternoon. In the still images - if not in life - it looked to be fairly easy to tell the presumed juveniles by their white-tipped underwing coverts; we were surprised though - again from examination of the images rather than noticing this in life - to see that some of the presumed adults (or at least, the ones that didn't have white-tipped coverts) gave the impression of being in moult. We'd always thought/imagined that Swifts didn't moult until arrival in their winter quarters and a quick check of the literature seems to confirm that, so now we're wondering if the apparent short secondaries that we initially took to be evidence of moult isn't just some sort of weird artefact generated by 'freezing' them in a photograph - that said though, it does appear to show up on quite a few images of several presumed different individual adults that are frozen in all manner of different postures, and a similar effect isn't apparent on any of the photographs of juveniles.