In article , David Rance
writes

All the above is true but red kites don't spread very fast - only a few
kilometres a year.

Yes, but this has now been going on for quite a few years so it's
conceivable that they have reached the south coast by now, though, to be
honest, I've not seen any on my trips down to Portsmouth

Oi looked at a 2014 year list of a birder on the IoW: so far he's only
seen red kites on a trip to the mainland.
It's clear from other records that they do turn up there occasionally.
They're working their way through Hampshire so they'll soon be as common
as seagulls.
--
Sue ]