The Golden Oriole - Britain's rarest bird?

There are a good few Golden Orioles dotted around the UK at the moment, it's true. However, aside of occasional continental vagrants breeding in the UK, it must be a contender for the rarest resident breeding species. RSPB Lakenheath Fen reserve is the only publicised location in the whole country where it can still be (pretty much) guaranteed to return to each Summer... and the sparse poplar plantation woods dotted around the East Anglian Fens are the only places it considers for nesting in full stop. Despite the impact of Global Warming, Orioles have suffered a major decline in the UK in recent years, and it is not even clear if the two singing males of 2010 and 2011 managed to attract a female - and thus nest - at all. The one filmed here is, again, one of two singing males that has turned up for Summer 2012... unfortunately, again, no female has yet to be spotted. Here's hoping it's simply because they are even harder to spot than the males! (NB Please skip to about 1:21 for the clearest view of the actual bird.)