Large gulls have been a particular focus this summer all for the wrong reasons. Reporters/journalists know next to nothing about them mainly picking up on the negatives drawing attention to what are genuinely interesting birds. There's so much to learn about gulls and there's always new things to learn. I've always had a keen interest in them, however I do struggle at the best of times with aging and ID if their not familiar and when you think you're getting there, you get a hybrid thrown in the mix like the Great Black-Backed Gull x Yellow Legged Gull of Richmond Bank a couple of years back but that's another story!
Caspian Gulls are one of the main reasons for people questioning ID... Is it? Isn't it? What are the ID features? Many Caspian Gulls that are called, are Yellow Legged Gulls or something else although numbers are increasing on the near continent and more are making it across to Britain. Slowly more and more people are getting to grips with what to look out for and the over all 'jizz' that screams out for a classic Casp.
One has spent most of it's time on Ainsdale beach, Lancs during the last 5 weeks as it undergoes a wing moult into a second winter plumage. With the bird reported showing down to a few metres, it suddenly dawned on me to why I hadn't been sooner.
I arrived not really knowing where to look... low tide, hordes of people, dogs barking, barbeques; you name it but not a gull in sight. As I looked beyond the chaos, there was one lone gull stood straight out towards the tideline... Looked liked the pics, surely can't be that easy?! On closer inspection, it was, and remarkably tame. With some of the stories of how people have been walking the length of the beach 5 or 6 times without a glimpse, I felt I had stroke it lucky.
There are many features that should be picked up on when identifying Caspian Gulls. Note the crisp, clean white head on this first summer bird and it's small dark/black beady eye which are also good indications on adult birds and something that can come in useful for when you're picking out birds in a gull roost. Luckily here it is stood on the beach giving close views and it's upright posture is one of the first things that should attract attention to a bird being questioned as a Caspian.
Caspian Gulls always have pale/white under-wings so if you have a bird in question without one, it certainly isn't a Caspian.
From a distance you can see it's clean white head stand out like a beacon - Herring and Yellow Legged Gulls have way more extensive streaking at all ages.
Juvenile and first summer birds have pinkish legs whereas adults have a lemon-yellow coloured legs. It's also worth noting that they're longer than Herring and Yellow Legged Gulls. Caspian Gulls have a long, slender bill which again came be quite distinctive at range.
This angle of the bird shows it's long sloping forehead and bill length. Although it is difficult to see as the bird is under-going moult but in a strong juvenile plumage, the greater coverts are quite finely patterned rather than more chequered like a Herring Gull/Yellow-Legged Gull would have.
Caspian Gulls are still a difficult bird to ID and even though one can't rule out a hybrid, traditionally, the main features talked about are generally a good indication that you'd be on to a winner. Getting a variety of pictures is also a vital piece to the puzzle as they can be used after to compare and check for finer details such as the amount of black colouration on the primaries
The bird at Ainsdale spent most of it's time on it's own only associating with the local Herring and Lesser Black-Backed Gulls when there was free food on offer. I used that as a good time to compare and contrast plumages. A real class, educational bird and well worth going to see if you have the time.