Thanks for the input, guys. I haven't heard the bird. I read it somewhere. I'm working on a book (fiction), where it's mentioned. Actually, it doesn't matter if I know or not, as the character doesn't know. He just hears it, and hears the words in the call.
But it's just one of those things that's niggling me. I wish I could remember which bird makes a call which sounds like that. I think it may be some kind of grouse. I don't know.
I got the idea for the scene from a documentary by Robert Perkins (Talking to Angels) - he was in the arctic, in a canoe, no one for hundreds, maybe thousands, of miles. He had gone into the wilderness to come to terms with a past where he was hospitalised for hearing voices (the angels in the title), and his wife's cancer, And there was this one scene where he was in his canoe, water slopping at its side, the evening still, and he turned the camera on himself. "Is it me," he said (or something along those lines), "or are those birds calling my name?" What first seemed a screech off in the distance, soon became recognizable as "Robert...Robert". Of course, they weren't calling out "Robert," but I have to say, listening to it, iI could feel the hairs on my neck stand on end.
But anyway, as I said, thanks for the input. I'll let you know if I ever track it down.