Gull query?

[2dogs2000]

A lot of blackheaded gulls have been flying close to the house recently but today I noticed that some of them have a black edge to the tail feathers and some don't. I wondered if there were two types of gull or is it just some are more mature than the others. They never seem to stop flying for me to make a better observation.

[Ferret]

Adult Black-headed Gulls have a clean white tail, sub-adult birds have a black terminal band. Hope that helps

Ferret

[2dogs2000]

That does help. Thank you.

[thebeard]

i seem to be seeing a lot near the house recenlty too, there were hundreds flying over last night in small flocks, probably going to roost, but in good numbers.