Long-tailed Duck on the S basin
sum. plum. Black-necked Grebe on the S basin
Back on the causeway, I picked up on a flock of 4 wader species in flight. Unfortunately, I only managed a short view through my bins so wasn't able to get a conclusive ID but given their plain grey appearance, white tail and rump and occasional flashes of black from their armpits, my best bet would be probable Grey Plover.
Also about were 2 Red Foxes resting on the edge of the reservoir a single Chiffchaff on the causeway and plenty of Goldeneyes on the open water.
Red Fox on the N basin
N basin at Staines Reservoir