Unknown Bird

Unknown bird call.m4a

Hi All,

I was hoping that someone would be able to help identify this bird from it's call (hopefully the file upload has worked). The bird was in a tree in the back garden of a terraced estate in Hereford. I was wondering if it might be a juvenile blackbird as I saw one entering the same tree but I have never heard this call before and I have seen plenty of junior blackbirds over the years.

Thanks in advance for any replies.