Help me identify this bird

[MinnieMountain]

No photo unfortunately.

-wagtail size and shape
-soft grey on top
-white from wings down
-a yellow flash under the wings
-no black on it
-seen on a bridge support on a Fenland river picking at the weed on it.

It didn't have enough yellow on it to be a yellow wagtail, which seem to have a whole yellow breast. This was definitely just a wide flash.

Can anyone help?

Was it a grey wagtail? They always have a bit of yellow on them - sometimes a lot and sometimes not much.

Yellowhammer?

Grey wagtails have a lovely flash of yellow and are found by rivers, sounds like that.

Grey wagtail

Pied wagtail

The rspb website have a bird a-z and a bird finder. www.rspb.org.uk

Let us know!

Ah, it could well be a grey wagtail. It was the smallness of the yellow patch that made me think not.

Yellow rumped warbler?

I would say grey wagtail as well. The size of the yellow patches can vary a lot and it could have been a juvenile which only have very small amounts of yellow.

@TheNestedIf Yellow rumped warbler is a North American species so it's very unlikely to be that I'm afraid.