A good 2 hour session between 1-3pm in glorious sunshine. Several Swallows were on telephone wires below the dam wall including both adults and juveniles - estimated c30.
As I climbed the hill towards the dam wall I heard the call of a Yellow Wagtail and 2 were catching flies with 10+ Pied Wagtails throughout my time on site.
Even better, as the western edge of the res became visible I could see a buzzard sized raptor quartering the shoreline which was a female Marsh Harrier. She flew up and down the res edge a few times before steadily gaining height and circling high above the water joined by 2 Buzzards.
Then, 10 minutes later, a Peregrine appeared low over the dam wall and again slowly circled a few times before gaining height. It appeared to be a juvenile with a full crop.
What a magical 20 minute spell of birding.