Scarce spring migrants around the net posts

On Thursday 30th March, at 5.50pm, I parked up by the net posts, just north of the Birds eye factory on the North Denies and as I got out of the car I could see an ash- grey female type Black Redstart perched on the nearest post it stayed there for a few short minutes but just flew as I was setting up my camera a dog walker had stopped and was looking with his dog at heel around 40 yards away but even at this range it had spooked the bird. Apparently it had flown to the bushes by the Birds Eye factory as I was informed by another birder from the big lens brigade (exact replica of mine!) It then flew onto the net posts again and was actively feeding at one time it caught a large caterpillar and being around 30 yards away we got some middling shots. As I was photographing this I heard the scratchy song of a male and what must be a male, albeit first year bird in ash grey plumage, the second Black Redstart, of the evening, was seeing on top of the middle of a horizontal post behind us. This birder promptly left, I was soon joined by another this time with a Sigma 150-600mm lens set up his only optical aid (what no bins!) and we saw a Wagtail flock actively feeding and moving initially by the grassy area just north- east of the net posts, various dog walkers were pushing them north- west from here. At least 3 were fine White Wagtails, 2 of them males.