Caspian hybrid? (2 Viewers)

[leifvester]

Related to this post, but didn't want to bump it / spam: Is this a Caspian gull? Ireland, North Coast

Heavily leaning towards the above being a hybrid, because I didn't originally account for the moult in the coverts.

Anyway, nearby was this adult Herring? Both eyes are dark. I assumed at the time just a dark eyed Herring, but that bill looks strange as well, and the body seems long.

 

[leifvester]

The underwing primaries from the same video clip. Seems a bit odd, not sure how much of that is motion blur though.
Only the primaries at the top (ignore the wing coming into frame on the bottom right - different gull)

I believe I have this gull on another clip, so I'll take a look at it too.

 

[leifvester]

The underwing primaries from the same video clip. Seems a bit odd, not sure how much of that is motion blur though.
Only the primaries at the top (ignore the wing coming into frame on the bottom right - different gull)

I believe I have this gull on another clip, so I'll take a look at it too.

This is the best photo I could grab from the same clip. Looks to be standard Argenteus. Not sure why the bird gave me such a strange impression.

 

[leifvester]

One thing I did notice was this gull in water.

It looked quite flat-backed in the water, but now I'm wondering how reliable this ID mark is, or it's more of an impression based field marker.

 

[leifvester]

Another weird one today, similar to OP.

A coincidence that it's another Herring with dark iris again in combination with an unusual bill.

I do wonder how much Caspian genes has flowed into Herring populations, because the hybrids can breed as well.

Is it any different to Carrion x Hooded which has a full hybrid spectrum?

EDIT: Well for this one anyway, definitely just a Herring. Comparison picture provided showing the bill to be shorter, thicker, and lacking the hooked tip. I mostly got confused by the markings on the bill, but these can be explained by the gull being sub-adult.
On the flip-side, I've attached a comparison with other random Herring profiles I found that I don't think I would have any doubt with. It does seem the gonys angle on this gull isn't very pronounced.
Quite a similar Herring here: ML614651623 - European Herring Gull - Macaulay Library