Rehabbed gull from Poland - ID needed! (1 Viewer)

[crithagra]

Welcome everyone! I hope I won’t upset anyone or get a perm for my first post 🙈 I’m a bird rehabber working at the Baltic coast. I’m rather confident about id’ing gulls but there’s always that one bird making trouble. It may seem dumb or unprofessional to ask about the species of a bird under my own care but I need a fresh perspective. Seeing her everyday doesn’t help you, you start to overthink things and it only makes you more confused.

Felicia is a bird who decided to spend her second winter in Gulf of Gdańsk, Poland. She was found at the end of October last year - injured, skinny and starving, emaciated and unable to fly. And since the day she was surrendered to me I wonder what the heck she is. Or more accurately - how much Caspian is in her. I primarily do ordinary herring gulls and visually she stays apart from them. She certainly has some Caspian features:

• eyes are rather dark(but not beady black)
• head and bill makes a little bit of Caspian’s ‘borzoi look’
• bill is not necessarily super long but has a slightly different shape than what I’m used to
• cleaner, whiter and less streaked patterns of head and neck making more mature look, just a little touch of black around the eyes
• belly and underparts are very white
• upper- and undertail coverts are almost patternless
• light underwings
• outer primaries have sharp white tongues on their inner webs(visible in one pic with raised wings on the ground), I’d associate it with Caspian more than the dull colored herring
• legs look longer and have a weird color - ‘they look super artificial, as if someone drained the whole blood from them’ my mum said(she’s definitely not a birder of any kind)
• and the whole silhouette seems off for a herring, kind of resembling a soldier standing at attention.

But - Caspians tend to moult faster than herrings, at this point(end of second winter) almost every Caspian of my bird’s age should have a so called grey saddle and some new wing coverts here and there. And she has just a few grey feathers at the back. Her moult timing is more similar to the slow herring. But there’s also another thing I’m aware of. If a gull’s health is compromised at the time of predicted moult, the whole moulting process can be skipped. I had a case like that with another gull after a tough surgery - he kept his entirely basic plumage throughout the summer and moulted again in late summer in post-breeding moult into basic plumage again. Going back to Felicia - she didn’t have any surgery but starved for some time so her autumn scapular moult into predicted 2nd winter plumage may be missed. Is this delay more a thing of health or species related issue? What do you think?

And if not a pure Caspian, then what? A 50/50 hybrid with herring? Some people suggested she may be a hybrid, maybe this is the right answer? Remember we’re in Poland. Poland is a hybrid zone for herrings and Caspians, and these hybrids breed again making genetic and visual mess. Some birds id’ed as pure Caspians here don’t look like textbook Caspians many people like to see as 1cy vagrants in UK. But I’m not sure, if she’s ‘caspianish’ enough for a Caspian? What’s your opinion?

 

[martyrynin]

I think IMG_5274 with the open wings and the tail look very Caspian to me. The base of the tail is very white, with some fine barring towards the tips of the tail feathers.

But definitely wait for another opinion!

Edit: There's a similar tail pattern on this Herring: Gull Research Organisation

 

[THE_FERN]

I think IMG_5274 with the open wings and the tail look very Caspian to me. The base of the tail is very white, with some fine barring towards the tips of the tail feathers.

But definitely wait for another opinion!

Surely the bill is too heavy and the tail band is thin and broken. Caspian would have a thin bill and thick tail band I think

 

[lou salomon]

The whole bird doesn't look like a 2nd cycle Caspian Gull at all. There might be a bit (but really only a bit) influence from Caspian but I certainly would have identified it as an argentatus. They are incredibly variable.

 

[lou salomon]

I've had a second look on this bird and, while still looking like a HG to me, there are two traits indicating cachinnans involvement: the pale ventral tongue to p10 which is larger than it should be in argentatus and the largely pale inner webs to p6 and p7 (probably extending to the outer 3 primaries also but not visible here). So, very likely it is a 'cactus' (argentatus x cachinnans), possibly a backcross.