Caspian, Yellow Legged and Herring Gulls (2 Viewers)

[Himalaya]

I have read a few online comments about Caspian Gulls displacing Herring Gulls as the former spreads West and North. Caspian Gulls are on average larger? I would have thought the more Northern race of Herring Gull would be the largest in this bunch. Also the Caspian Gull beak looks longer but not as deep? On average Caspian Gulls do have longer legs it seems too.

I have always thought Yellow Legged Gulls appear larger too, on average. How do they compare diet wise?

 

[pdwinter]

In terms of length, wingspan and weight they are all roughly the same size.
This article is quite interesting (well to me, anyway!)

https://gull-research.org/cachinnans/polska/images01/June21CaspianGulls.pdf

 

[Micealh]

Here in Ireland very little doubt that Caspian is going under-identified and thus remains a ‘mega’.

 

[HH75]

Here in Ireland very little doubt that Caspian is going under-identified and thus remains a ‘mega’.

While I agree with you insomuch as Caspian Gull is under-recorded here in Ireland...due to a combination of low observer numbers, identification issues and many birders just not really putting in effort looking at large gulls...the species is also rare in, say, SW England, Wales and so on. We probably genuinely get relatively few, but this may change as the spread continues.

 

[vergan]

Here in Ireland very little doubt that Caspian is going under-identified and thus remains a ‘mega’.

I would say it is genuinely rare there. That's why you have mucho more neartic gulls and less middle eastern gulls like, for example, the netherlands.

 

[Dyrlege]

Don't these hybridize as well? I'm certainly sure I have problems differentiating them.

 

[HH75]

I would say it is genuinely rare there. That's why you have mucho more neartic gulls and less middle eastern gulls like, for example, the netherlands.

Mediterranean Gulls are locally 'common' nowadays, with a growing breeding population even, but, as recently as the 1970s, when it had become a scarce but regular visitor to Britain, it was still a rarity in Ireland. Given the current westward push of breeding Caspian Gulls, they may be expected to become more regular here, too, even if they remain a rare bird it may progress to where we get a few every year.