Fly Flatts

This morning - I found 2 Fox Moth caterpillars at the northern end - this one was eating grass stalk (purple moor grass ? ) near an area of sparse heather with the other one nearby.

If anyone can help with these dragonflies I found around the new ponds that would be a help.
I am thinking Black Darter maybe - but it's a new one to me ! or more likely I have not noticed them before !!
Front one (male?) is dark and the other (female?) - yellowish with a slightly larger body.
They were not as large as Common Hawker (maybe half the size) but buzzed around pretty quickly so it was difficult to get any really good shots.