What type of bird did I see? It doesn’t seem to exist!

[TheFreaksShallInheritTheEarth]

At the end of last week, I saw two birds mating on the rail of my balcony. They looked very unfamiliar, so I got DD to look, too.

I looked online and couldn’t identify it there. I bought a bird identification book from Amazon as I’d been meaning to anyway, but it doesn’t seem to exist! I suppose it’s a visitor passing through, but even those should appear in British bird books if they’re regular visitors?

Anyway, it was small: tit size and shape (roundish) and was predominantly black (true black) with a solid red flash on the side of its head or collar. DD says there was a bit of white on its chest.

We’re in South West Wales, rural area, near the coast.

Any ideas? Thanks!

One has been spotted in Orkney though so he's a possible.

The female is nothing like the OP described though.

Not any of the things pictured, alas... can’t remember the beak, but the whole “look” was small and tit like.

Yes, I guess there would be individual variation, and age related variation, but there were two of them, and they looked identical

The swallow and red winged blackbird are closest in look.

Long tailed tit not black enough

Thanks for all suggestions.

I have to go out now, but may return with diagram later!

The swallow and red winged blackbird are closest in look

Should have added the red-backed fairywren to that list. That’s actually the closest.

The rear view at the end of the feeding video shows the back to be predominantly black. Map shows there has been a sighting in south Wales before.
www.rarebirdalert.co.uk/v2/Content/Finders_in_the_field_Rose_breasted_Grosbeak_West_Burra_Shetland_May_2016.aspx?s_id=798977449