We've had a pair of grey wagtails in the garden a couple of times over the last week or two but the robin chases them off before I can get a photo. Never had them before in the garden & I noticed you said they were unusual visitors for you too Geumlover, perhaps they're starting to visit gardens more often nowadays like lots of birds due to loss of their natural habitats etc.
I don't think the few that have visited so far will cause much damage Rosie but I suppose if they become residents it could eventually have an impact. They were eating all sorts on Autumnwatch including dragonflies & I looked them up & they eat lots of insects including bees, wasps, dragonflies & hornets - perhaps they'll get rid of that massive Asian hornet which is threatening to move over here! There was a study done in Spain which showed bee eaters didn't have a big impact on honey bees as they ate less than 1 percent of worker bees in their area so maybe not so bad.
I call 'him' Rocky - he's very feisty & chases everything out of the garden, he was looking through the patio doors here yesterday morning whilst chasing the squirrel around the patio as it buried nuts/acorns!
Thought I'd share this with you. I'd put a piece of stale cake on the tray on the feeding station on Saturday. I looked out the window yesterday afternoon to see a large number of starlings pushing it across the lawn whilst squabbling over it. At which point a seagull descended and flew off with it in it's beak!
Starlings are never happy unless they're squabbling are they! We have had a jay & a woodpecker in the garden briefly this weekend, haven't seen the woodpecker since last year I think, I suppose the weather must be turning wintry & bringing them into gardens.