Bird ID Required Please, by Sound...

[LeGingeur]

Hi all,

Although I live in Yorkshire, during the week I live in Hampshire, and my lodgings back on to a wood. It's a great place for birds, what with Buzzards and Great Spotted Woodpeckers and a pair of Tawny Owls that hoot their way through the night. Lately, however, I've noticed a new sound. It's a very strident call, similar in tone and pitch to the call of the Small-Eared Owl (listen here - the second half after the hoots), but runs in three sets of triplets playing notes E moving down to C then up to A. The first two notes in each phrase are slurred, and each set of triplets takes about a second. I only hear it at night.

I know it's a shot in the dark but can anyone help with the identification please? I've been through just about all the birds on the RSPB's website!

Thanks,

Math