Bird Call Id Pleae

[hc4361]

I am on a tidal estuary in Wales. Lots of ducks, gulls, swans, egrets, wading birds as well as crows, Martin's and garden birds.
There is a very small island with trees and shrubs and this is where the bird is coming from.
I hear it as WOCAWOC as if made with a wobble board. It is loud but not raucous or shrill.

All suggestions welcome.

[rowanwitch]

Where exactly are you...

You could work your way through the RSPB guide as most of the birds have a soundfile with them.

[rowanwitch]

http://www.rspb.org.uk/birds-and-wildlife/bird-and-wildlife-guides/bird-a-z/c/cormorant/index.aspx

Cormorant is my first thought

[rowanwitch]

Shelduck
http://www.rspb.org.uk/birds-and-wildlife/bird-and-wildlife-guides/bird-a-z/s/shelduck/index.aspx

[ducksie]

this youtube link plays the sounds from birds in UK, pictures of them and their names, I'd keep listening but it's too relaxing and making me sleepy I'm sure I heard a WOCAWOC in the 1st 8 ;)