Monday, 3 September 2012


I took a trip out to Southend, Essex on Sunday to check out the urban birding for a forthcoming piece in Birdwatching Magazine. Having not visited this famous seaside town since the devil was a boy, it was like I had never been before. I was pleasantly surprised. There were many places both in the town and surrounding areas for some decent birding.

I took a walk along Southend Pier with my host Emily Broad. As we neared the end of the pier we came across around 40 Common Terns variously fishing along side the pier or resting along the side of the structure. I was photographing a couple of the birds resting on the side rail when I happened across a couple of terns, standing between two obvious Common Terns, that didn't quite fit the identikit. They seemed slighter with shorter and thinner legs. Plumage-wise, they seemingly resembled Common Terns
moulting into winter plumage - but something was odd about them. Tern number 2 even appeared to have a orangy tip to its bill.

I put the image out on Twitter and Facebook to solicit the opinions of fellow birders. The response was strongly divided. Some people were thinking that tern number 2 was a juvenile Black Tern, a Roseate Tern and several people were convinced they were looking at a Sandwich Tern. A couple people even suggested that they were both hybrids.
Odd tern no.1
Odd tern no.2 note the spindly legs
 A closer view of no.1
 No.1 with an summer adult Common Tern check out the delicate build
 1 & 2 together. No. 2 has a slightly shorter bill and even thinner legs
 A classic Common Tern
The most likely answer is that they were both Common Terns. Why? Well, they are both adult birds moulting into their winter plumages. Arctic Terns moult in their winter quarters, so are rarely seen in that plumage in the UK. Furthermore, they would not show so much black in the wing and have darker shorter bills. Sandwich Terns are altogether larger birds with longer black legs. Roseate Terns should display longer tail streamers and longer legs. Finally, the plumage and larger size is totally wrong for Black Tern.

All that said, I still have a problem with them, particularly tern no.2. Some people have said that the legs appear shorter because the belly feathers are fluffed out. Even if that was the case, how does that explain their thin appearance?

I'm still not wholly convinced of their identity, but hey, that is the beauty of birding: nothing ever looks exactly as they do in the books!

Not like this lovely Ruddy Turnstone - a lot more straight forward.
A lovely Ruddy Turnstone

1 comment:

Cloud Cuckoo said...

David, nice post. Enjoy puzzles. My instant reaction is that 1 is Common and 2 is Arctic. I used to watch lots of terns closely off the Nothe in Weymouth and saw lots of tricky ones like these. Not all terns obey the books. I frequently saw imm Common (2nd summer I guess) which should have been off Africa, and in odd moult states. I think 1 is probably one of these. 2 just screams Arctic, except the tail doesn't look long enough at this angle. The moult may be wrong, but as I said, not all the birds read their bird books!.