An unusual date and an interesting bird. To me it looks rather compact and rounded winged compared to northern birds which typically have the second to fifth primaries of a similar length. As this bird does not appear to be moult (I'm not great on pernis ageing but I think this is a juvenile/first-winter), I wonder if it a southerly breeder; i.e. of the subspecies ruficollis. As this is potential split this is quite an interesting record.
Are there more photographs?