thomaslegg

Sorry for the crummy photos, but the light was flat and this gull was pretty high. Flew into the area, circled a few times, and then flew out of sight in the direction of DB.

I don't get much practice here with gull id, but is this a black-tailed gull?

John Holmes

Possibly Heuglins Gull ?

Black-tailed Gull immatures are milk coffee-coloured, and the pink bill should have a black tip.

thomaslegg

Given the nature of the photos, I expected that it'd end up as "gull sp." Now worried my attempts to lighten the photos to look at underwing colouring and possible wing tip mirrors might have upset the ID attempts. So I'm attaching an untouched version of one of the photos.



I'm curious as to why you think it's an immature bird.

and half of my guess on Black-tailed Gull was wondering if it was this same bird that had been hanging around Nim Shue Wan (Discovery Bay) and Peng Chau the first couple of weeks last May 2019.

ajohn

It's definitely an immature bird - the underparts and underwings are quite dark and with darker mottling. An adult of any species should be largely white below.
So it's definitely not the (adult) bird you linked to from last spring.

I'm not entirely sure about ID. Like John H I don't think it's Black-tailed, and Heuglin's is probably the most likely. Best to leave it as gull sp. I think.